651566715441621 has 64 divisors (see below), whose sum is σ = 1040171762073600. Its totient is φ = 354910666795776.

The previous prime is 651566715441611. The next prime is 651566715441623. The reversal of 651566715441621 is 126144517665156.

It is not a de Polignac number, because 651566715441621 - 2¹¹ = 651566715439573 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (651566715441623) 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 63 ways as a sum of consecutive naturals, for example, 723765040 + ... + 724664726.

It is an arithmetic number, because the mean of its divisors is an integer number (16252683782400).

Almost surely, 2^{651566715441621} is an apocalyptic number.

It is an amenable number.

651566715441621 is a deficient number, since it is larger than the sum of its proper divisors (388605046631979).

651566715441621 is a wasteful number, since it uses less digits than its factorization.

651566715441621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 914858.

The product of its digits is 36288000, while the sum is 60.

The spelling of 651566715441621 in words is "six hundred fifty-one trillion, five hundred sixty-six billion, seven hundred fifteen million, four hundred forty-one thousand, six hundred twenty-one".