665915461 has 4 divisors (see below), whose sum is σ = 675294624. Its totient is φ = 656536300.

The previous prime is 665915431. The next prime is 665915519. The reversal of 665915461 is 164519566.

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 a cyclic number.

It is not a de Polignac number, because 665915461 - 2²³ = 657526853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665915431) 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, 4689475 + ... + 4689616.

It is an arithmetic number, because the mean of its divisors is an integer number (168823656).

Almost surely, 2^665915461 is an apocalyptic number.

It is an amenable number.

665915461 is a deficient number, since it is larger than the sum of its proper divisors (9379163).

665915461 is an equidigital number, since it uses as much as digits as its factorization.

665915461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9379162.

The product of its digits is 194400, while the sum is 43.

The square root of 665915461 is about 25805.3378392921. The cubic root of 665915461 is about 873.2522221189.

The spelling of 665915461 in words is "six hundred sixty-five million, nine hundred fifteen thousand, four hundred sixty-one".