165570551 has 2 divisors, whose sum is σ = 165570552. Its totient is φ = 165570550.

The previous prime is 165570547. The next prime is 165570553. The reversal of 165570551 is 155075561.

It is a strong prime.

It is an emirp because it is prime and its reverse (155075561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165570551 - 2² = 165570547 is a prime.

Together with 165570553, 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 (165570553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82785275 + 82785276.

It is an arithmetic number, because the mean of its divisors is an integer number (82785276).

Almost surely, 2^165570551 is an apocalyptic number.

165570551 is a deficient number, since it is larger than the sum of its proper divisors (1).

165570551 is an equidigital number, since it uses as much as digits as its factorization.

165570551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 26250, while the sum is 35.

The square root of 165570551 is about 12867.4220805879. The cubic root of 165570551 is about 549.1121222707.

The spelling of 165570551 in words is "one hundred sixty-five million, five hundred seventy thousand, five hundred fifty-one".