21540045524 has 12 divisors (see below), whose sum is σ = 38614472148. Its totient is φ = 10507339200.

The previous prime is 21540045523. The next prime is 21540045547. The reversal of 21540045524 is 42554004512.

It can be written as a sum of positive squares in 2 ways, for example, as 11365692100 + 10174353424 = 106610^2 + 100868^2 .

It is a super-2 number, since 2×21540045524² (a number of 21 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21540045523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65670707 + ... + 65671034.

It is an arithmetic number, because the mean of its divisors is an integer number (3217872679).

Almost surely, 2^21540045524 is an apocalyptic number.

It is an amenable number.

21540045524 is a deficient number, since it is larger than the sum of its proper divisors (17074426624).

21540045524 is a wasteful number, since it uses less digits than its factorization.

21540045524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131341786 (or 131341784 counting only the distinct ones).

The product of its (nonzero) digits is 32000, while the sum is 32.

The spelling of 21540045524 in words is "twenty-one billion, five hundred forty million, forty-five thousand, five hundred twenty-four".