165877661 has 2 divisors, whose sum is σ = 165877662. Its totient is φ = 165877660.

The previous prime is 165877637. The next prime is 165877667. The reversal of 165877661 is 166778561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 165122500 + 755161 = 12850^2 + 869^2 .

It is a cyclic number.

It is not a de Polignac number, because 165877661 - 2⁶ = 165877597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165877667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82938830 + 82938831.

It is an arithmetic number, because the mean of its divisors is an integer number (82938831).

Almost surely, 2^165877661 is an apocalyptic number.

It is an amenable number.

165877661 is a deficient number, since it is larger than the sum of its proper divisors (1).

165877661 is an equidigital number, since it uses as much as digits as its factorization.

165877661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 423360, while the sum is 47.

The square root of 165877661 is about 12879.3501777069. The cubic root of 165877661 is about 549.4514210645.

The spelling of 165877661 in words is "one hundred sixty-five million, eight hundred seventy-seven thousand, six hundred sixty-one".