651668917 has 4 divisors (see below), whose sum is σ = 662352076. Its totient is φ = 640985760.

The previous prime is 651668881. The next prime is 651668929. The reversal of 651668917 is 719866156.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 205234276 + 446434641 = 14326^2 + 21129^2 .

It is a cyclic number.

It is not a de Polignac number, because 651668917 - 2⁷ = 651668789 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 (651668977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5341488 + ... + 5341609.

It is an arithmetic number, because the mean of its divisors is an integer number (165588019).

Almost surely, 2^651668917 is an apocalyptic number.

It is an amenable number.

651668917 is a deficient number, since it is larger than the sum of its proper divisors (10683159).

651668917 is a wasteful number, since it uses less digits than its factorization.

651668917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10683158.

The product of its digits is 544320, while the sum is 49.

The square root of 651668917 is about 25527.8067408855. The cubic root of 651668917 is about 866.9798466935.

The spelling of 651668917 in words is "six hundred fifty-one million, six hundred sixty-eight thousand, nine hundred seventeen".