161877857 has 2 divisors, whose sum is σ = 161877858. Its totient is φ = 161877856.

The previous prime is 161877827. The next prime is 161877899. The reversal of 161877857 is 758778161.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 131583841 + 30294016 = 11471^2 + 5504^2 .

It is a cyclic number.

It is not a de Polignac number, because 161877857 - 2¹⁴ = 161861473 is a prime.

It is not a weakly prime, because it can be changed into another prime (161877827) 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, 80938928 + 80938929.

It is an arithmetic number, because the mean of its divisors is an integer number (80938929).

Almost surely, 2^161877857 is an apocalyptic number.

It is an amenable number.

161877857 is a deficient number, since it is larger than the sum of its proper divisors (1).

161877857 is an equidigital number, since it uses as much as digits as its factorization.

161877857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 658560, while the sum is 50.

The square root of 161877857 is about 12723.1229263888. The cubic root of 161877857 is about 544.9991381183. Note that the first 3 decimals are identical.

The spelling of 161877857 in words is "one hundred sixty-one million, eight hundred seventy-seven thousand, eight hundred fifty-seven".