665974511 has 4 divisors (see below), whose sum is σ = 666747072. Its totient is φ = 665201952.

The previous prime is 665974483. The next prime is 665974513. The reversal of 665974511 is 115479566.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665974511 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 (665974513) 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, 384986 + ... + 386711.

It is an arithmetic number, because the mean of its divisors is an integer number (166686768).

Almost surely, 2^665974511 is an apocalyptic number.

665974511 is a deficient number, since it is larger than the sum of its proper divisors (772561).

665974511 is an equidigital number, since it uses as much as digits as its factorization.

665974511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 772560.

The product of its digits is 226800, while the sum is 44.

The square root of 665974511 is about 25806.4819570588. The cubic root of 665974511 is about 873.2780332128.

The spelling of 665974511 in words is "six hundred sixty-five million, nine hundred seventy-four thousand, five hundred eleven".