165900961 has 2 divisors, whose sum is σ = 165900962. Its totient is φ = 165900960.

The previous prime is 165900901. The next prime is 165900983. The reversal of 165900961 is 169009561.

165900961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 165894400 + 6561 = 12880^2 + 81^2 .

It is a cyclic number.

It is not a de Polignac number, because 165900961 - 2¹⁵ = 165868193 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 165900961.

It is not a weakly prime, because it can be changed into another prime (165900901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82950480 + 82950481.

It is an arithmetic number, because the mean of its divisors is an integer number (82950481).

Almost surely, 2^165900961 is an apocalyptic number.

It is an amenable number.

165900961 is a deficient number, since it is larger than the sum of its proper divisors (1).

165900961 is an equidigital number, since it uses as much as digits as its factorization.

165900961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14580, while the sum is 37.

The square root of 165900961 is about 12880.2546946867. The cubic root of 165900961 is about 549.4771460850.

The spelling of 165900961 in words is "one hundred sixty-five million, nine hundred thousand, nine hundred sixty-one".