21124417972 has 24 divisors (see below), whose sum is σ = 43045986816. Its totient is φ = 8882503968.

The previous prime is 21124417961. The next prime is 21124418017. The reversal of 21124417972 is 27971442112.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7115908 + ... + 7118875.

It is an arithmetic number, because the mean of its divisors is an integer number (1793582784).

Almost surely, 2^21124417972 is an apocalyptic number.

It is an amenable number.

21124417972 is an abundant number, since it is smaller than the sum of its proper divisors (21921568844).

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

21124417972 is a wasteful number, since it uses less digits than its factorization.

21124417972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14234847 (or 14234845 counting only the distinct ones).

The product of its digits is 56448, while the sum is 40.

The spelling of 21124417972 in words is "twenty-one billion, one hundred twenty-four million, four hundred seventeen thousand, nine hundred seventy-two".