21313508 has 12 divisors (see below), whose sum is σ = 37348080. Its totient is φ = 10642632.

The previous prime is 21313493. The next prime is 21313531. The reversal of 21313508 is 80531312.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 335 + ... + 6537.

It is an arithmetic number, because the mean of its divisors is an integer number (3112340).

Almost surely, 2^21313508 is an apocalyptic number.

It is an amenable number.

21313508 is a deficient number, since it is larger than the sum of its proper divisors (16034572).

21313508 is a wasteful number, since it uses less digits than its factorization.

21313508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7066 (or 7064 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 21313508 is about 4616.6554993848. The cubic root of 21313508 is about 277.2585698732.

The spelling of 21313508 in words is "twenty-one million, three hundred thirteen thousand, five hundred eight".