856920929 has 2 divisors, whose sum is σ = 856920930. Its totient is φ = 856920928.

The previous prime is 856920893. The next prime is 856920931. The reversal of 856920929 is 929029658.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 522213904 + 334707025 = 22852^2 + 18295^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-856920929 is a prime.

Together with 856920931, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (856920329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428460464 + 428460465.

It is an arithmetic number, because the mean of its divisors is an integer number (428460465).

Almost surely, 2^856920929 is an apocalyptic number.

It is an amenable number.

856920929 is a deficient number, since it is larger than the sum of its proper divisors (1).

856920929 is an equidigital number, since it uses as much as digits as its factorization.

856920929 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 699840, while the sum is 50.

The square root of 856920929 is about 29273.2117985027. The cubic root of 856920929 is about 949.8322617975.

The spelling of 856920929 in words is "eight hundred fifty-six million, nine hundred twenty thousand, nine hundred twenty-nine".