665574651 has 20 divisors (see below), whose sum is σ = 1136290672. Its totient is φ = 380328048.

The previous prime is 665574649. The next prime is 665574671. The reversal of 665574651 is 156475566.

665574651 is a `hidden beast` number, since 6 + 6 + 557 + 46 + 51 = 666.

It is not a de Polignac number, because 665574651 - 2¹ = 665574649 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 665574597 and 665574606.

It is not an unprimeable number, because it can be changed into a prime (665574631) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 586360 + ... + 587493.

Almost surely, 2^665574651 is an apocalyptic number.

665574651 is a deficient number, since it is larger than the sum of its proper divisors (470716021).

665574651 is a wasteful number, since it uses less digits than its factorization.

665574651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1173872 (or 1173863 counting only the distinct ones).

The product of its digits is 756000, while the sum is 45.

The square root of 665574651 is about 25798.7335154267. The cubic root of 665574651 is about 873.1032222865.

The spelling of 665574651 in words is "six hundred sixty-five million, five hundred seventy-four thousand, six hundred fifty-one".