21581021682234 has 128 divisors (see below), whose sum is σ = 54864843264000. Its totient is φ = 6159720734784.

The previous prime is 21581021682193. The next prime is 21581021682247. The reversal of 21581021682234 is 43228612018512.

21581021682234 is a `hidden beast` number, since 2 + 1 + 581 + 0 + 2 + 1 + 68 + 2 + 2 + 3 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21581021682234.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2335856587 + ... + 2335865825.

It is an arithmetic number, because the mean of its divisors is an integer number (428631588000).

Almost surely, 2^{21581021682234} is an apocalyptic number.

21581021682234 is an abundant number, since it is smaller than the sum of its proper divisors (33283821581766).

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

21581021682234 is a wasteful number, since it uses less digits than its factorization.

21581021682234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14889 (or 14883 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The spelling of 21581021682234 in words is "twenty-one trillion, five hundred eighty-one billion, twenty-one million, six hundred eighty-two thousand, two hundred thirty-four".