165451997 has 2 divisors, whose sum is σ = 165451998. Its totient is φ = 165451996.

The previous prime is 165451907. The next prime is 165451999. The reversal of 165451997 is 799154561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 163302841 + 2149156 = 12779^2 + 1466^2 .

It is an emirp because it is prime and its reverse (799154561) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165451997 is a prime.

It is a super-2 number, since 2×165451997² = 54748726622576018, which contains 22 as substring.

Together with 165451999, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165451999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82725998 + 82725999.

It is an arithmetic number, because the mean of its divisors is an integer number (82725999).

Almost surely, 2^165451997 is an apocalyptic number.

It is an amenable number.

165451997 is a deficient number, since it is larger than the sum of its proper divisors (1).

165451997 is an equidigital number, since it uses as much as digits as its factorization.

165451997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 340200, while the sum is 47.

The square root of 165451997 is about 12862.8145053872. The cubic root of 165451997 is about 548.9810301529.

The spelling of 165451997 in words is "one hundred sixty-five million, four hundred fifty-one thousand, nine hundred ninety-seven".