8991980971 has 2 divisors, whose sum is σ = 8991980972. Its totient is φ = 8991980970.

The previous prime is 8991980953. The next prime is 8991981013. The reversal of 8991980971 is 1790891998.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 8991980971 - 2³¹ = 6844497323 is a prime.

It is a super-2 number, since 2×8991980971² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (8991980771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4495990485 + 4495990486.

It is an arithmetic number, because the mean of its divisors is an integer number (4495990486).

Almost surely, 2^8991980971 is an apocalyptic number.

8991980971 is a deficient number, since it is larger than the sum of its proper divisors (1).

8991980971 is an equidigital number, since it uses as much as digits as its factorization.

8991980971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2939328, while the sum is 61.

The square root of 8991980971 is about 94826.0563927447. The cubic root of 8991980971 is about 2079.4658523480.

The spelling of 8991980971 in words is "eight billion, nine hundred ninety-one million, nine hundred eighty thousand, nine hundred seventy-one".