665427657 has 4 divisors (see below), whose sum is σ = 887236880. Its totient is φ = 443618436.

The previous prime is 665427643. The next prime is 665427677. The reversal of 665427657 is 756724566.

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 665427657 - 2⁴ = 665427641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665427677) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110904607 + ... + 110904612.

It is an arithmetic number, because the mean of its divisors is an integer number (221809220).

Almost surely, 2^665427657 is an apocalyptic number.

It is an amenable number.

665427657 is a deficient number, since it is larger than the sum of its proper divisors (221809223).

665427657 is a wasteful number, since it uses less digits than its factorization.

665427657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221809222.

The product of its digits is 2116800, while the sum is 48.

The square root of 665427657 is about 25795.8844973379. The cubic root of 665427657 is about 873.0389418013.

The spelling of 665427657 in words is "six hundred sixty-five million, four hundred twenty-seven thousand, six hundred fifty-seven".