165815651 has 2 divisors, whose sum is σ = 165815652. Its totient is φ = 165815650.

The previous prime is 165815627. The next prime is 165815669. The reversal of 165815651 is 156518561.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165815651 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (165817651) 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, 82907825 + 82907826.

It is an arithmetic number, because the mean of its divisors is an integer number (82907826).

Almost surely, 2^165815651 is an apocalyptic number.

165815651 is a deficient number, since it is larger than the sum of its proper divisors (1).

165815651 is an equidigital number, since it uses as much as digits as its factorization.

165815651 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36000, while the sum is 38.

The square root of 165815651 is about 12876.9426107287. The cubic root of 165815651 is about 549.3829454402.

The spelling of 165815651 in words is "one hundred sixty-five million, eight hundred fifteen thousand, six hundred fifty-one".