665372761 has 16 divisors (see below), whose sum is σ = 712656000. Its totient is φ = 619411968.

The previous prime is 665372753. The next prime is 665372767. The reversal of 665372761 is 167273566.

It is a cyclic number.

It is not a de Polignac number, because 665372761 - 2³ = 665372753 is a prime.

It is a super-2 number, since 2×665372761² = 885441822161526242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (665372767) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 273396 + ... + 275818.

It is an arithmetic number, because the mean of its divisors is an integer number (44541000).

Almost surely, 2^665372761 is an apocalyptic number.

It is an amenable number.

665372761 is a deficient number, since it is larger than the sum of its proper divisors (47283239).

665372761 is a wasteful number, since it uses less digits than its factorization.

665372761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2688.

The product of its digits is 317520, while the sum is 43.

The square root of 665372761 is about 25794.8204296909. The cubic root of 665372761 is about 873.0149333494.

The spelling of 665372761 in words is "six hundred sixty-five million, three hundred seventy-two thousand, seven hundred sixty-one".