651256323661 has 8 divisors (see below), whose sum is σ = 673735416120. Its totient is φ = 628778696448.

The previous prime is 651256323637. The next prime is 651256323733. The reversal of 651256323661 is 166323652156.

It can be written as a sum of positive squares in 4 ways, for example, as 151698565225 + 499557758436 = 389485^2 + 706794^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 651256323661 - 2⁹ = 651256323149 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 (651256323631) 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 7 ways as a sum of consecutive naturals, for example, 579385 + ... + 1279921.

It is an arithmetic number, because the mean of its divisors is an integer number (84216927015).

Almost surely, 2^651256323661 is an apocalyptic number.

It is an amenable number.

651256323661 is a deficient number, since it is larger than the sum of its proper divisors (22479092459).

651256323661 is a wasteful number, since it uses less digits than its factorization.

651256323661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 732623.

The product of its digits is 1166400, while the sum is 46.

The spelling of 651256323661 in words is "six hundred fifty-one billion, two hundred fifty-six million, three hundred twenty-three thousand, six hundred sixty-one".