165977857 has 2 divisors, whose sum is σ = 165977858. Its totient is φ = 165977856.

The previous prime is 165977843. The next prime is 165977891. The reversal of 165977857 is 758779561.

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., 162409536 + 3568321 = 12744^2 + 1889^2 .

It is an emirp because it is prime and its reverse (758779561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165977857 - 2¹¹ = 165975809 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 165977798 and 165977807.

It is not a weakly prime, because it can be changed into another prime (165977957) 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, 82988928 + 82988929.

It is an arithmetic number, because the mean of its divisors is an integer number (82988929).

Almost surely, 2^165977857 is an apocalyptic number.

It is an amenable number.

165977857 is a deficient number, since it is larger than the sum of its proper divisors (1).

165977857 is an equidigital number, since it uses as much as digits as its factorization.

165977857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3704400, while the sum is 55.

The square root of 165977857 is about 12883.2393830123. The cubic root of 165977857 is about 549.5620281897.

The spelling of 165977857 in words is "one hundred sixty-five million, nine hundred seventy-seven thousand, eight hundred fifty-seven".