665369257 has 4 divisors (see below), whose sum is σ = 760422016. Its totient is φ = 570316500.

The previous prime is 665369219. The next prime is 665369291. The reversal of 665369257 is 752963566.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 752963566 = 2 ⋅376481783.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665369257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 665369257.

It is not an unprimeable number, because it can be changed into a prime (665369207) 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, 47526369 + ... + 47526382.

It is an arithmetic number, because the mean of its divisors is an integer number (190105504).

Almost surely, 2^665369257 is an apocalyptic number.

It is an amenable number.

665369257 is a deficient number, since it is larger than the sum of its proper divisors (95052759).

665369257 is an equidigital number, since it uses as much as digits as its factorization.

665369257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95052758.

The product of its digits is 2041200, while the sum is 49.

The square root of 665369257 is about 25794.7525089891. The cubic root of 665369257 is about 873.0134008502.

The spelling of 665369257 in words is "six hundred sixty-five million, three hundred sixty-nine thousand, two hundred fifty-seven".