21540532 has 12 divisors (see below), whose sum is σ = 40595716. Its totient is φ = 9941760.

The previous prime is 21540529. The next prime is 21540551. The reversal of 21540532 is 23504512.

It can be written as a sum of positive squares in 2 ways, for example, as 5588496 + 15952036 = 2364^2 + 3994^2 .

It is a hoax number, since the sum of its digits (22) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 207069 + ... + 207172.

Almost surely, 2^21540532 is an apocalyptic number.

It is an amenable number.

21540532 is a deficient number, since it is larger than the sum of its proper divisors (19055184).

21540532 is a wasteful number, since it uses less digits than its factorization.

21540532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414258 (or 414256 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 21540532 is about 4641.1778677400. The cubic root of 21540532 is about 278.2395154738.

The spelling of 21540532 in words is "twenty-one million, five hundred forty thousand, five hundred thirty-two".