9971614781 has 2 divisors, whose sum is σ = 9971614782. Its totient is φ = 9971614780.

The previous prime is 9971614777. The next prime is 9971614819. The reversal of 9971614781 is 1874161799.

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., 8922502681 + 1049112100 = 94459^2 + 32390^2 .

It is a cyclic number.

It is not a de Polignac number, because 9971614781 - 2² = 9971614777 is a prime.

It is a super-2 number, since 2×9971614781² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9971614711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4985807390 + 4985807391.

It is an arithmetic number, because the mean of its divisors is an integer number (4985807391).

Almost surely, 2^9971614781 is an apocalyptic number.

It is an amenable number.

9971614781 is a deficient number, since it is larger than the sum of its proper divisors (1).

9971614781 is an equidigital number, since it uses as much as digits as its factorization.

9971614781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 762048, while the sum is 53.

The square root of 9971614781 is about 99857.9730467227. The cubic root of 9971614781 is about 2152.3942882207.

The spelling of 9971614781 in words is "nine billion, nine hundred seventy-one million, six hundred fourteen thousand, seven hundred eighty-one".