857161979 has 2 divisors, whose sum is σ = 857161980. Its totient is φ = 857161978.

The previous prime is 857161933. The next prime is 857161993. The reversal of 857161979 is 979161758.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-857161979 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 857161979.

It is not a weakly prime, because it can be changed into another prime (857161909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428580989 + 428580990.

It is an arithmetic number, because the mean of its divisors is an integer number (428580990).

Almost surely, 2^857161979 is an apocalyptic number.

857161979 is a deficient number, since it is larger than the sum of its proper divisors (1).

857161979 is an equidigital number, since it uses as much as digits as its factorization.

857161979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 952560, while the sum is 53.

The square root of 857161979 is about 29277.3287545158. The cubic root of 857161979 is about 949.9213153667.

The spelling of 857161979 in words is "eight hundred fifty-seven million, one hundred sixty-one thousand, nine hundred seventy-nine".