9972664621 has 2 divisors, whose sum is σ = 9972664622. Its totient is φ = 9972664620.

The previous prime is 9972664607. The next prime is 9972664717. The reversal of 9972664621 is 1264662799.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9818035396 + 154629225 = 99086^2 + 12435^2 .

It is a cyclic number.

It is not a de Polignac number, because 9972664621 - 2⁵ = 9972664589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9972664421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4986332310 + 4986332311.

It is an arithmetic number, because the mean of its divisors is an integer number (4986332311).

Almost surely, 2^9972664621 is an apocalyptic number.

It is an amenable number.

9972664621 is a deficient number, since it is larger than the sum of its proper divisors (1).

9972664621 is an equidigital number, since it uses as much as digits as its factorization.

9972664621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1959552, while the sum is 52.

The square root of 9972664621 is about 99863.2295742532. The cubic root of 9972664621 is about 2152.4698223033.

The spelling of 9972664621 in words is "nine billion, nine hundred seventy-two million, six hundred sixty-four thousand, six hundred twenty-one".