20877971 has 2 divisors, whose sum is σ = 20877972. Its totient is φ = 20877970.

The previous prime is 20877959. The next prime is 20877991. The reversal of 20877971 is 17977802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20877971 - 2⁶ = 20877907 is a prime.

It is not a weakly prime, because it can be changed into another prime (20877931) 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 as a sum of consecutive naturals, namely, 10438985 + 10438986.

It is an arithmetic number, because the mean of its divisors is an integer number (10438986).

Almost surely, 2^20877971 is an apocalyptic number.

20877971 is a deficient number, since it is larger than the sum of its proper divisors (1).

20877971 is an equidigital number, since it uses as much as digits as its factorization.

20877971 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 49392, while the sum is 41.

The square root of 20877971 is about 4569.2418408309. The cubic root of 20877971 is about 275.3569843232.

The spelling of 20877971 in words is "twenty million, eight hundred seventy-seven thousand, nine hundred seventy-one".