165256251 has 4 divisors (see below), whose sum is σ = 220341672. Its totient is φ = 110170832.

The previous prime is 165256249. The next prime is 165256253. The reversal of 165256251 is 152652561.

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

It is an interprime number because it is at equal distance from previous prime (165256249) and next prime (165256253).

It is a cyclic number.

It is not a de Polignac number, because 165256251 - 2¹ = 165256249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165256253) 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, 27542706 + ... + 27542711.

It is an arithmetic number, because the mean of its divisors is an integer number (55085418).

Almost surely, 2^165256251 is an apocalyptic number.

165256251 is a deficient number, since it is larger than the sum of its proper divisors (55085421).

165256251 is an equidigital number, since it uses as much as digits as its factorization.

165256251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55085420.

The product of its digits is 18000, while the sum is 33.

The square root of 165256251 is about 12855.2032656042. The cubic root of 165256251 is about 548.7644451827.

The spelling of 165256251 in words is "one hundred sixty-five million, two hundred fifty-six thousand, two hundred fifty-one".