165215451 has 4 divisors (see below), whose sum is σ = 220287272. Its totient is φ = 110143632.

The previous prime is 165215447. The next prime is 165215459. The reversal of 165215451 is 154512561.

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

It is not a de Polignac number, because 165215451 - 2² = 165215447 is a prime.

It is a super-2 number, since 2×165215451² = 54592290498266802, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165215459) 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, 27535906 + ... + 27535911.

It is an arithmetic number, because the mean of its divisors is an integer number (55071818).

Almost surely, 2^165215451 is an apocalyptic number.

165215451 is a deficient number, since it is larger than the sum of its proper divisors (55071821).

165215451 is an equidigital number, since it uses as much as digits as its factorization.

165215451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55071820.

The product of its digits is 6000, while the sum is 30.

The square root of 165215451 is about 12853.6162615818. The cubic root of 165215451 is about 548.7192801091.

The spelling of 165215451 in words is "one hundred sixty-five million, two hundred fifteen thousand, four hundred fifty-one".