21121552024 has 8 divisors (see below), whose sum is σ = 39602910060. Its totient is φ = 10560776008.

The previous prime is 21121552019. The next prime is 21121552031. The reversal of 21121552024 is 42025512112.

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×21121552024² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21121552024.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1320096994 + ... + 1320097009.

Almost surely, 2^21121552024 is an apocalyptic number.

It is an amenable number.

21121552024 is a deficient number, since it is larger than the sum of its proper divisors (18481358036).

21121552024 is a wasteful number, since it uses less digits than its factorization.

21121552024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2640194009 (or 2640194005 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 25.

The spelling of 21121552024 in words is "twenty-one billion, one hundred twenty-one million, five hundred fifty-two thousand, twenty-four".