21540512 has 96 divisors (see below), whose sum is σ = 52399872. Its totient is φ = 8515584.

The previous prime is 21540473. The next prime is 21540529. The reversal of 21540512 is 21504512.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 190568 + ... + 190680.

It is an arithmetic number, because the mean of its divisors is an integer number (545832).

Almost surely, 2^21540512 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 21540512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26199936).

21540512 is an abundant number, since it is smaller than the sum of its proper divisors (30859360).

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

21540512 is a wasteful number, since it uses less digits than its factorization.

21540512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190 (or 182 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 21540512 is about 4641.1757131141. The cubic root of 21540512 is about 278.2394293603.

The spelling of 21540512 in words is "twenty-one million, five hundred forty thousand, five hundred twelve".