21268558 has 12 divisors (see below), whose sum is σ = 32185440. Its totient is φ = 10540856.

The previous prime is 21268553. The next prime is 21268567. The reversal of 21268558 is 85586212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21268553) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 44163 + ... + 44641.

It is an arithmetic number, because the mean of its divisors is an integer number (2682120).

Almost surely, 2^21268558 is an apocalyptic number.

21268558 is a deficient number, since it is larger than the sum of its proper divisors (10916882).

21268558 is an equidigital number, since it uses as much as digits as its factorization.

21268558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 779 (or 630 counting only the distinct ones).

The product of its digits is 38400, while the sum is 37.

The square root of 21268558 is about 4611.7846870816. The cubic root of 21268558 is about 277.0635207321.

The spelling of 21268558 in words is "twenty-one million, two hundred sixty-eight thousand, five hundred fifty-eight".