9920648971 has 2 divisors, whose sum is σ = 9920648972. Its totient is φ = 9920648970.

The previous prime is 9920648921. The next prime is 9920648977. The reversal of 9920648971 is 1798460299.

It is a strong prime.

It is an emirp because it is prime and its reverse (1798460299) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9920648971 is a prime.

It is not a weakly prime, because it can be changed into another prime (9920648977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4960324485 + 4960324486.

It is an arithmetic number, because the mean of its divisors is an integer number (4960324486).

Almost surely, 2^9920648971 is an apocalyptic number.

9920648971 is a deficient number, since it is larger than the sum of its proper divisors (1).

9920648971 is an equidigital number, since it uses as much as digits as its factorization.

9920648971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1959552, while the sum is 55.

The square root of 9920648971 is about 99602.4546434474. The cubic root of 9920648971 is about 2148.7209967091.

The spelling of 9920648971 in words is "nine billion, nine hundred twenty million, six hundred forty-eight thousand, nine hundred seventy-one".