20936579 has 4 divisors (see below), whose sum is σ = 21658560. Its totient is φ = 20214600.

The previous prime is 20936567. The next prime is 20936581. The reversal of 20936579 is 97563902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97563902 = 2 ⋅48781951.

It is a cyclic number.

It is not a de Polignac number, because 20936579 - 2¹⁶ = 20871043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20936549) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 360947 + ... + 361004.

It is an arithmetic number, because the mean of its divisors is an integer number (5414640).

Almost surely, 2^20936579 is an apocalyptic number.

20936579 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

20936579 is a deficient number, since it is larger than the sum of its proper divisors (721981).

20936579 is an equidigital number, since it uses as much as digits as its factorization.

20936579 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 721980.

The product of its (nonzero) digits is 102060, while the sum is 41.

The square root of 20936579 is about 4575.6506641132. The cubic root of 20936579 is about 275.6144014963.

The spelling of 20936579 in words is "twenty million, nine hundred thirty-six thousand, five hundred seventy-nine".