21450521524 has 24 divisors (see below), whose sum is σ = 38838693600. Its totient is φ = 10353863520.

The previous prime is 21450521497. The next prime is 21450521527. The reversal of 21450521524 is 42512505412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21450521527) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1254867 + ... + 1271845.

It is an arithmetic number, because the mean of its divisors is an integer number (1618278900).

Almost surely, 2^21450521524 is an apocalyptic number.

It is an amenable number.

21450521524 is a deficient number, since it is larger than the sum of its proper divisors (17388172076).

21450521524 is a wasteful number, since it uses less digits than its factorization.

21450521524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27903 (or 27901 counting only the distinct ones).

The product of its (nonzero) digits is 16000, while the sum is 31.

The spelling of 21450521524 in words is "twenty-one billion, four hundred fifty million, five hundred twenty-one thousand, five hundred twenty-four".