213561631800 has 288 divisors, whose sum is σ = 809394066000. Its totient is φ = 49987123200.

The previous prime is 213561631769. The next prime is 213561631813. The reversal of 213561631800 is 8136165312.

213561631800 is a `hidden beast` number, since 2 + 1 + 3 + 5 + 616 + 31 + 8 + 0 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 388236 + ... + 760164.

Almost surely, 2^213561631800 is an apocalyptic number.

213561631800 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 213561631800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (404697033000).

213561631800 is an abundant number, since it is smaller than the sum of its proper divisors (595832434200).

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

213561631800 is a wasteful number, since it uses less digits than its factorization.

213561631800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371991 (or 371979 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The spelling of 213561631800 in words is "two hundred thirteen billion, five hundred sixty-one million, six hundred thirty-one thousand, eight hundred".