651299681 has 2 divisors, whose sum is σ = 651299682. Its totient is φ = 651299680.

The previous prime is 651299657. The next prime is 651299707. The reversal of 651299681 is 186992156.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 474542656 + 176757025 = 21784^2 + 13295^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-651299681 is a prime.

It is a super-2 number, since 2×651299681² = 848382548941403522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (651299281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 325649840 + 325649841.

It is an arithmetic number, because the mean of its divisors is an integer number (325649841).

Almost surely, 2^651299681 is an apocalyptic number.

It is an amenable number.

651299681 is a deficient number, since it is larger than the sum of its proper divisors (1).

651299681 is an equidigital number, since it uses as much as digits as its factorization.

651299681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 233280, while the sum is 47.

The square root of 651299681 is about 25520.5736808560. The cubic root of 651299681 is about 866.8160719906.

The spelling of 651299681 in words is "six hundred fifty-one million, two hundred ninety-nine thousand, six hundred eighty-one".