21328734 has 16 divisors (see below), whose sum is σ = 48751488. Its totient is φ = 6093912.

The previous prime is 21328729. The next prime is 21328753. The reversal of 21328734 is 43782312.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 253872 + ... + 253955.

It is an arithmetic number, because the mean of its divisors is an integer number (3046968).

Almost surely, 2^21328734 is an apocalyptic number.

21328734 is an abundant number, since it is smaller than the sum of its proper divisors (27422754).

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

21328734 is a wasteful number, since it uses less digits than its factorization.

21328734 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 507839.

The product of its digits is 8064, while the sum is 30.

The square root of 21328734 is about 4618.3042342401. The cubic root of 21328734 is about 277.3245770601.

The spelling of 21328734 in words is "twenty-one million, three hundred twenty-eight thousand, seven hundred thirty-four".