9971402981 has 2 divisors, whose sum is σ = 9971402982. Its totient is φ = 9971402980.

The previous prime is 9971402971. The next prime is 9971403011. The reversal of 9971402981 is 1892041799.

9971402981 = 70609² + 70610².

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4985772100 + 4985630881 = 70610^2 + 70609^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9971402981 is a prime.

It is a super-2 number, since 2×9971402981² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9971402971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4985701490 + 4985701491.

It is an arithmetic number, because the mean of its divisors is an integer number (4985701491).

Almost surely, 2^9971402981 is an apocalyptic number.

9971402981 is the 70610-th centered square number.

It is an amenable number.

9971402981 is a deficient number, since it is larger than the sum of its proper divisors (1).

9971402981 is an equidigital number, since it uses as much as digits as its factorization.

9971402981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 326592, while the sum is 50.

The square root of 9971402981 is about 99856.9125348866. The cubic root of 9971402981 is about 2152.3790489525.

The spelling of 9971402981 in words is "nine billion, nine hundred seventy-one million, four hundred two thousand, nine hundred eighty-one".