21166579 has 12 divisors (see below), whose sum is σ = 24734808. Its totient is φ = 18060000.

The previous prime is 21166567. The next prime is 21166597. The reversal of 21166579 is 97566112.

It is not a de Polignac number, because 21166579 - 2¹⁷ = 21035507 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21166529) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11439 + ... + 13159.

It is an arithmetic number, because the mean of its divisors is an integer number (2061234).

Almost surely, 2^21166579 is an apocalyptic number.

21166579 is a deficient number, since it is larger than the sum of its proper divisors (3568229).

21166579 is a wasteful number, since it uses less digits than its factorization.

21166579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1986 (or 1979 counting only the distinct ones).

The product of its digits is 22680, while the sum is 37.

The square root of 21166579 is about 4600.7150531195. The cubic root of 21166579 is about 276.6199874474.

The spelling of 21166579 in words is "twenty-one million, one hundred sixty-six thousand, five hundred seventy-nine".