20927857 has 2 divisors, whose sum is σ = 20927858. Its totient is φ = 20927856.

The previous prime is 20927843. The next prime is 20927887. The reversal of 20927857 is 75872902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13830961 + 7096896 = 3719^2 + 2664^2 .

It is a cyclic number.

It is not a de Polignac number, because 20927857 - 2²³ = 12539249 is a prime.

It is a super-2 number, since 2×20927857² = 875950397224898, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20927807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10463928 + 10463929.

It is an arithmetic number, because the mean of its divisors is an integer number (10463929).

Almost surely, 2^20927857 is an apocalyptic number.

It is an amenable number.

20927857 is a deficient number, since it is larger than the sum of its proper divisors (1).

20927857 is an equidigital number, since it uses as much as digits as its factorization.

20927857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 70560, while the sum is 40.

The square root of 20927857 is about 4574.6974763366. The cubic root of 20927857 is about 275.5761233118.

The spelling of 20927857 in words is "twenty million, nine hundred twenty-seven thousand, eight hundred fifty-seven".