21293579 has 2 divisors, whose sum is σ = 21293580. Its totient is φ = 21293578.

The previous prime is 21293563. The next prime is 21293599. The reversal of 21293579 is 97539212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21293579 - 2⁴ = 21293563 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21293599) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10646789 + 10646790.

It is an arithmetic number, because the mean of its divisors is an integer number (10646790).

Almost surely, 2^21293579 is an apocalyptic number.

21293579 is a deficient number, since it is larger than the sum of its proper divisors (1).

21293579 is an equidigital number, since it uses as much as digits as its factorization.

21293579 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34020, while the sum is 38.

The square root of 21293579 is about 4614.4966139331. The cubic root of 21293579 is about 277.1721268982.

The spelling of 21293579 in words is "twenty-one million, two hundred ninety-three thousand, five hundred seventy-nine".