185138208 has 72 divisors (see below), whose sum is σ = 527806188. Its totient is φ = 61558272.

The previous prime is 185138207. The next prime is 185138209. The reversal of 185138208 is 802831581.

It is an interprime number because it is at equal distance from previous prime (185138207) and next prime (185138209).

It can be written as a sum of positive squares in 2 ways, for example, as 141419664 + 43718544 = 11892^2 + 6612^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×185138208² = 68552312122902528, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (185138207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 210666 + ... + 211542.

Almost surely, 2^185138208 is an apocalyptic number.

185138208 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 185138208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263903094).

185138208 is an abundant number, since it is smaller than the sum of its proper divisors (342667980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

185138208 is a wasteful number, since it uses less digits than its factorization.

185138208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1626 (or 1615 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The square root of 185138208 is about 13606.5501873179. The cubic root of 185138208 is about 569.9437802354.

Adding to 185138208 its reverse (802831581), we get a palindrome (987969789).

The spelling of 185138208 in words is "one hundred eighty-five million, one hundred thirty-eight thousand, two hundred eight".