20879879 has 6 divisors (see below), whose sum is σ = 22037040. Its totient is φ = 19780596.

The previous prime is 20879869. The next prime is 20879909. The reversal of 20879879 is 97897802.

It is a happy number.

It is not a de Polignac number, because 20879879 - 2⁴ = 20879863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20879809) 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 5 ways as a sum of consecutive naturals, for example, 28559 + ... + 29280.

It is an arithmetic number, because the mean of its divisors is an integer number (3672840).

Almost surely, 2^20879879 is an apocalyptic number.

20879879 is a deficient number, since it is larger than the sum of its proper divisors (1157161).

20879879 is an equidigital number, since it uses as much as digits as its factorization.

20879879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57877 (or 57858 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 50.

The square root of 20879879 is about 4569.4506234338. The cubic root of 20879879 is about 275.3653721932.

The spelling of 20879879 in words is "twenty million, eight hundred seventy-nine thousand, eight hundred seventy-nine".