21313528 has 8 divisors (see below), whose sum is σ = 39962880. Its totient is φ = 10656760.

The previous prime is 21313493. The next prime is 21313531. The reversal of 21313528 is 82531312.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1332088 + ... + 1332103.

It is an arithmetic number, because the mean of its divisors is an integer number (4995360).

Almost surely, 2^21313528 is an apocalyptic number.

It is an amenable number.

21313528 is a deficient number, since it is larger than the sum of its proper divisors (18649352).

21313528 is a wasteful number, since it uses less digits than its factorization.

21313528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2664197 (or 2664193 counting only the distinct ones).

The product of its digits is 1440, while the sum is 25.

The square root of 21313528 is about 4616.6576654545. The cubic root of 21313528 is about 277.2586565971.

The spelling of 21313528 in words is "twenty-one million, three hundred thirteen thousand, five hundred twenty-eight".