21924057816 has 24 divisors (see below), whose sum is σ = 59377656780. Its totient is φ = 7308019248.

The previous prime is 21924057791. The next prime is 21924057821. The reversal of 21924057816 is 61875042912.

21924057816 is a `hidden beast` number, since 21 + 9 + 2 + 40 + 578 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×21924057816² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 152250330 + ... + 152250473.

Almost surely, 2^21924057816 is an apocalyptic number.

It is an amenable number.

21924057816 is an abundant number, since it is smaller than the sum of its proper divisors (37453598964).

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

21924057816 is a wasteful number, since it uses less digits than its factorization.

21924057816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304500815 (or 304500808 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The spelling of 21924057816 in words is "twenty-one billion, nine hundred twenty-four million, fifty-seven thousand, eight hundred sixteen".