213661800 has 360 divisors, whose sum is σ = 823156950. Its totient is φ = 51321600.

The previous prime is 213661793. The next prime is 213661801. The reversal of 213661800 is 8166312.

It can be written as a sum of positive squares in 3 ways, for example, as 175986756 + 37675044 = 13266^2 + 6138^2 .

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (213661801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 89 ways as a sum of consecutive naturals, for example, 1960146 + ... + 1960254.

Almost surely, 2^213661800 is an apocalyptic number.

213661800 is a gapful number since it is divisible by the number (20) 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 213661800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (411578475).

213661800 is an abundant number, since it is smaller than the sum of its proper divisors (609495150).

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

213661800 is a wasteful number, since it uses less digits than its factorization.

213661800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 213661800 is about 14617.1748296311. The cubic root of 213661800 is about 597.8271406358.

It can be divided in two parts, 2136 and 61800, that added together give a palindrome (63936).

The spelling of 213661800 in words is "two hundred thirteen million, six hundred sixty-one thousand, eight hundred".