21655364012004 has 24 divisors (see below), whose sum is σ = 50531382840960. Its totient is φ = 7218140364064.

The previous prime is 21655364012003. The next prime is 21655364012017. The reversal of 21655364012004 is 40021046355612.

It is not an unprimeable number, because it can be changed into a prime (21655364012003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39001164 + ... + 39552515.

It is an arithmetic number, because the mean of its divisors is an integer number (2105474285040).

Almost surely, 2^{21655364012004} is an apocalyptic number.

It is an amenable number.

21655364012004 is an abundant number, since it is smaller than the sum of its proper divisors (28876018828956).

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

21655364012004 is a wasteful number, since it uses less digits than its factorization.

21655364012004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78576659 (or 78576657 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 39.

The spelling of 21655364012004 in words is "twenty-one trillion, six hundred fifty-five billion, three hundred sixty-four million, twelve thousand, four".