665157 has 4 divisors (see below), whose sum is σ = 886880. Its totient is φ = 443436.

The previous prime is 665153. The next prime is 665177. The reversal of 665157 is 751566.

665157 is nontrivially palindromic in base 2.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 665157 - 2² = 665153 is a prime.

It is a D-number.

It is a Duffinian number.

665157 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665153) 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, 110857 + ... + 110862.

It is an arithmetic number, because the mean of its divisors is an integer number (221720).

2⁶⁶⁵¹⁵⁷ is an apocalyptic number.

It is an amenable number.

665157 is a deficient number, since it is larger than the sum of its proper divisors (221723).

665157 is a wasteful number, since it uses less digits than its factorization.

665157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221722.

The product of its digits is 6300, while the sum is 30.

The square root of 665157 is about 815.5715787103. The cubic root of 665157 is about 87.2920558712.

The spelling of 665157 in words is "six hundred sixty-five thousand, one hundred fifty-seven".