664061751 has 12 divisors (see below), whose sum is σ = 977299128. Its totient is φ = 434354544.

The previous prime is 664061747. The next prime is 664061759. The reversal of 664061751 is 157160466.

664061751 is a `hidden beast` number, since 6 + 640 + 6 + 1 + 7 + 5 + 1 = 666.

It is not a de Polignac number, because 664061751 - 2² = 664061747 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664061759) 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 11 ways as a sum of consecutive naturals, for example, 695605 + ... + 696558.

It is an arithmetic number, because the mean of its divisors is an integer number (81441594).

Almost surely, 2^664061751 is an apocalyptic number.

664061751 is a deficient number, since it is larger than the sum of its proper divisors (313237377).

664061751 is a wasteful number, since it uses less digits than its factorization.

664061751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1392222 (or 1392219 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 664061751 is about 25769.3956273716. The cubic root of 664061751 is about 872.4411778529.

The spelling of 664061751 in words is "six hundred sixty-four million, sixty-one thousand, seven hundred fifty-one".