181431616 has 56 divisors (see below), whose sum is σ = 385145280. Its totient is φ = 84498432.

The previous prime is 181431587. The next prime is 181431617. The reversal of 181431616 is 616134181.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181431617) 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 7 ways as a sum of consecutive naturals, for example, 111255 + ... + 112873.

Almost surely, 2^181431616 is an apocalyptic number.

181431616 is a gapful number since it is divisible by the number (16) 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 181431616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (192572640).

181431616 is an abundant number, since it is smaller than the sum of its proper divisors (203713664).

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

181431616 is a wasteful number, since it uses less digits than its factorization.

181431616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1751 (or 1741 counting only the distinct ones).

The product of its digits is 3456, while the sum is 31.

The square root of 181431616 is about 13469.6553779226. The cubic root of 181431616 is about 566.1145576742.

Adding to 181431616 its reverse (616134181), we get a palindrome (797565797).

The spelling of 181431616 in words is "one hundred eighty-one million, four hundred thirty-one thousand, six hundred sixteen".