20905879 has 8 divisors (see below), whose sum is σ = 21278592. Its totient is φ = 20535480.

The previous prime is 20905877. The next prime is 20905901. The reversal of 20905879 is 97850902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20905879 - 2¹ = 20905877 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 (20905877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36852 + ... + 37414.

It is an arithmetic number, because the mean of its divisors is an integer number (2659824).

Almost surely, 2^20905879 is an apocalyptic number.

20905879 is a deficient number, since it is larger than the sum of its proper divisors (372713).

20905879 is an equidigital number, since it uses as much as digits as its factorization.

20905879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1157.

The product of its (nonzero) digits is 45360, while the sum is 40.

The square root of 20905879 is about 4572.2947192848. The cubic root of 20905879 is about 275.4796214188.

The spelling of 20905879 in words is "twenty million, nine hundred five thousand, eight hundred seventy-nine".