665403653651 has 32 divisors (see below), whose sum is σ = 800631406080. Its totient is φ = 545883148800.

The previous prime is 665403653627. The next prime is 665403653671. The reversal of 665403653651 is 156356304566.

It is a de Polignac number, because none of the positive numbers 2^k-665403653651 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 665403653651.

It is not an unprimeable number, because it can be changed into a prime (665403653671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 871301 + ... + 1445673.

It is an arithmetic number, because the mean of its divisors is an integer number (25019731440).

Almost surely, 2^665403653651 is an apocalyptic number.

665403653651 is a deficient number, since it is larger than the sum of its proper divisors (135227752429).

665403653651 is a wasteful number, since it uses less digits than its factorization.

665403653651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 574667.

The product of its (nonzero) digits is 5832000, while the sum is 50.

The spelling of 665403653651 in words is "six hundred sixty-five billion, four hundred three million, six hundred fifty-three thousand, six hundred fifty-one".