165997477 has 2 divisors, whose sum is σ = 165997478. Its totient is φ = 165997476.

The previous prime is 165997459. The next prime is 165997511. The reversal of 165997477 is 774799561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 130165281 + 35832196 = 11409^2 + 5986^2 .

It is an emirp because it is prime and its reverse (774799561) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165997477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165997277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82998738 + 82998739.

It is an arithmetic number, because the mean of its divisors is an integer number (82998739).

Almost surely, 2^165997477 is an apocalyptic number.

It is an amenable number.

165997477 is a deficient number, since it is larger than the sum of its proper divisors (1).

165997477 is an equidigital number, since it uses as much as digits as its factorization.

165997477 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3333960, while the sum is 55.

The square root of 165997477 is about 12884.0008149643. Note that the first 3 decimals coincide. The cubic root of 165997477 is about 549.5836816447.

The spelling of 165997477 in words is "one hundred sixty-five million, nine hundred ninety-seven thousand, four hundred seventy-seven".