21328258 has 32 divisors (see below), whose sum is σ = 38016000. Its totient is φ = 8784720.

The previous prime is 21328247. The next prime is 21328273. The reversal of 21328258 is 85282312.

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, 42493 + ... + 42991.

It is an arithmetic number, because the mean of its divisors is an integer number (1188000).

Almost surely, 2^21328258 is an apocalyptic number.

21328258 is a deficient number, since it is larger than the sum of its proper divisors (16687742).

21328258 is a wasteful number, since it uses less digits than its factorization.

21328258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622.

The product of its digits is 7680, while the sum is 31.

The square root of 21328258 is about 4618.2526998855. The cubic root of 21328258 is about 277.3225139984.

The spelling of 21328258 in words is "twenty-one million, three hundred twenty-eight thousand, two hundred fifty-eight".