21456858 has 16 divisors (see below), whose sum is σ = 43960896. Its totient is φ = 6977760.

The previous prime is 21456829. The next prime is 21456859. The reversal of 21456858 is 85865412.

It is not an unprimeable number, because it can be changed into a prime (21456859) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43366 + ... + 43857.

It is an arithmetic number, because the mean of its divisors is an integer number (2747556).

Almost surely, 2^21456858 is an apocalyptic number.

21456858 is an abundant number, since it is smaller than the sum of its proper divisors (22504038).

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

21456858 is a wasteful number, since it uses less digits than its factorization.

21456858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87269.

The product of its digits is 76800, while the sum is 39.

The square root of 21456858 is about 4632.1547901598. The cubic root of 21456858 is about 277.8787750191.

The spelling of 21456858 in words is "twenty-one million, four hundred fifty-six thousand, eight hundred fifty-eight".