21662458 has 16 divisors (see below), whose sum is σ = 34376256. Its totient is φ = 10216800.

The previous prime is 21662453. The next prime is 21662461. The reversal of 21662458 is 85426612.

It is not an unprimeable number, because it can be changed into a prime (21662453) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 133 + ... + 6583.

It is an arithmetic number, because the mean of its divisors is an integer number (2148516).

Almost surely, 2^21662458 is an apocalyptic number.

21662458 is a deficient number, since it is larger than the sum of its proper divisors (12713798).

21662458 is a wasteful number, since it uses less digits than its factorization.

21662458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6549.

The product of its digits is 23040, while the sum is 34.

The square root of 21662458 is about 4654.2945759803. The cubic root of 21662458 is about 278.7635016619.

It can be divided in two parts, 2166 and 2458, that added together give a square (4624 = 68²).

The spelling of 21662458 in words is "twenty-one million, six hundred sixty-two thousand, four hundred fifty-eight".