21121725804 has 48 divisors (see below), whose sum is σ = 50666073696. Its totient is φ = 6844364800.

The previous prime is 21121725799. The next prime is 21121725851. The reversal of 21121725804 is 40852712112.

It is a super-2 number, since 2×21121725804² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61864 + ... + 214640.

It is an arithmetic number, because the mean of its divisors is an integer number (1055543202).

Almost surely, 2^21121725804 is an apocalyptic number.

It is an amenable number.

21121725804 is an abundant number, since it is smaller than the sum of its proper divisors (29544347892).

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

21121725804 is a wasteful number, since it uses less digits than its factorization.

21121725804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153106 (or 153104 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 33.

The spelling of 21121725804 in words is "twenty-one billion, one hundred twenty-one million, seven hundred twenty-five thousand, eight hundred four".