665106651 has 24 divisors (see below), whose sum is σ = 1049580480. Its totient is φ = 402505200.

The previous prime is 665106649. The next prime is 665106653. The reversal of 665106651 is 156601566.

It is an interprime number because it is at equal distance from previous prime (665106649) and next prime (665106653).

It is not a de Polignac number, because 665106651 - 2¹ = 665106649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (665106653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68616 + ... + 77706.

It is an arithmetic number, because the mean of its divisors is an integer number (43732520).

Almost surely, 2^665106651 is an apocalyptic number.

665106651 is a deficient number, since it is larger than the sum of its proper divisors (384473829).

665106651 is a wasteful number, since it uses less digits than its factorization.

665106651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9847 (or 9844 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 665106651 is about 25789.6617077464. The cubic root of 665106651 is about 872.8985329417.

The spelling of 665106651 in words is "six hundred sixty-five million, one hundred six thousand, six hundred fifty-one".