21457287124 has 72 divisors (see below), whose sum is σ = 46531412928. Its totient is φ = 8477314560.

The previous prime is 21457287107. The next prime is 21457287149. The reversal of 21457287124 is 42178275412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4166319 + ... + 4171465.

It is an arithmetic number, because the mean of its divisors is an integer number (646269624).

Almost surely, 2^21457287124 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 21457287124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23265706464).

21457287124 is an abundant number, since it is smaller than the sum of its proper divisors (25074125804).

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

21457287124 is a wasteful number, since it uses less digits than its factorization.

21457287124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6065 (or 6050 counting only the distinct ones).

The product of its digits is 250880, while the sum is 43.

The spelling of 21457287124 in words is "twenty-one billion, four hundred fifty-seven million, two hundred eighty-seven thousand, one hundred twenty-four".