21263541056604 has 768 divisors, whose sum is σ = 71923396608000. Its totient is φ = 5271076823040.

The previous prime is 21263541056591. The next prime is 21263541056627. The reversal of 21263541056604 is 40665014536212.

21263541056604 is a `hidden beast` number, since 2 + 1 + 2 + 6 + 35 + 4 + 1 + 0 + 5 + 6 + 604 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21263541056604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 22888633612 + ... + 22888634540.

It is an arithmetic number, because the mean of its divisors is an integer number (93650256000).

Almost surely, 2^{21263541056604} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21263541056604, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35961698304000).

21263541056604 is an abundant number, since it is smaller than the sum of its proper divisors (50659855551396).

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

21263541056604 is a wasteful number, since it uses less digits than its factorization.

21263541056604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1983 (or 1975 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 45.

The spelling of 21263541056604 in words is "twenty-one trillion, two hundred sixty-three billion, five hundred forty-one million, fifty-six thousand, six hundred four".