21540712 has 16 divisors (see below), whose sum is σ = 40549860. Its totient is φ = 10727424.

The previous prime is 21540709. The next prime is 21540731. The reversal of 21540712 is 21704512.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17189316 + 4351396 = 4146^2 + 2086^2 .

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, 3183 + ... + 7294.

Almost surely, 2^21540712 is an apocalyptic number.

It is an amenable number.

21540712 is a deficient number, since it is larger than the sum of its proper divisors (19009148).

21540712 is a wasteful number, since it uses less digits than its factorization.

21540712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10740 (or 10736 counting only the distinct ones).

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21540712 is about 4641.1972593287. The cubic root of 21540712 is about 278.2402904929.

The spelling of 21540712 in words is "twenty-one million, five hundred forty thousand, seven hundred twelve".