20811879 has 36 divisors (see below), whose sum is σ = 34234200. Its totient is φ = 12159840.

The previous prime is 20811853. The next prime is 20811883. The reversal of 20811879 is 97811802.

It is not a de Polignac number, because 20811879 - 2⁷ = 20811751 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20811899) 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 35 ways as a sum of consecutive naturals, for example, 31252 + ... + 31910.

It is an arithmetic number, because the mean of its divisors is an integer number (950950).

Almost surely, 2^20811879 is an apocalyptic number.

20811879 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

20811879 is a deficient number, since it is larger than the sum of its proper divisors (13422321).

20811879 is a wasteful number, since it uses less digits than its factorization.

20811879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 716 (or 702 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 20811879 is about 4562.0038360352. The cubic root of 20811879 is about 275.0661174356.

The spelling of 20811879 in words is "twenty million, eight hundred eleven thousand, eight hundred seventy-nine".