165134551 has 4 divisors (see below), whose sum is σ = 170461504. Its totient is φ = 159807600.

The previous prime is 165134537. The next prime is 165134573. The reversal of 165134551 is 155431561.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165134551 - 2⁷ = 165134423 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31), and also a Moran number because the ratio is a prime number: 5326921 = 165134551 / (1 + 6 + 5 + 1 + 3 + 4 + 5 + 5 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165134521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2663430 + ... + 2663491.

It is an arithmetic number, because the mean of its divisors is an integer number (42615376).

Almost surely, 2^165134551 is an apocalyptic number.

165134551 is a deficient number, since it is larger than the sum of its proper divisors (5326953).

165134551 is an equidigital number, since it uses as much as digits as its factorization.

165134551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5326952.

The product of its digits is 9000, while the sum is 31.

The square root of 165134551 is about 12850.4689019506. The cubic root of 165134551 is about 548.6297028590.

The spelling of 165134551 in words is "one hundred sixty-five million, one hundred thirty-four thousand, five hundred fifty-one".