9899263721 has 2 divisors, whose sum is σ = 9899263722. Its totient is φ = 9899263720.

The previous prime is 9899263669. The next prime is 9899263723. The reversal of 9899263721 is 1273629989.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7610119696 + 2289144025 = 87236^2 + 47845^2 .

It is an emirp because it is prime and its reverse (1273629989) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 9899263721 - 2²² = 9895069417 is a prime.

Together with 9899263723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (9899263723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4949631860 + 4949631861.

It is an arithmetic number, because the mean of its divisors is an integer number (4949631861).

Almost surely, 2^9899263721 is an apocalyptic number.

It is an amenable number.

9899263721 is a deficient number, since it is larger than the sum of its proper divisors (1).

9899263721 is an equidigital number, since it uses as much as digits as its factorization.

9899263721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2939328, while the sum is 56.

The square root of 9899263721 is about 99495.0437006789. The cubic root of 9899263721 is about 2147.1759367314.

The spelling of 9899263721 in words is "nine billion, eight hundred ninety-nine million, two hundred sixty-three thousand, seven hundred twenty-one".