998164842721 has 2 divisors, whose sum is σ = 998164842722. Its totient is φ = 998164842720.

The previous prime is 998164842673. The next prime is 998164842743. The reversal of 998164842721 is 127248461899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 895483690000 + 102681152721 = 946300^2 + 320439^2 .

It is a cyclic number.

It is not a de Polignac number, because 998164842721 - 2²⁷ = 998030624993 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 998164842721.

It is not a weakly prime, because it can be changed into another prime (998164842221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499082421360 + 499082421361.

It is an arithmetic number, because the mean of its divisors is an integer number (499082421361).

Almost surely, 2^998164842721 is an apocalyptic number.

It is an amenable number.

998164842721 is a deficient number, since it is larger than the sum of its proper divisors (1).

998164842721 is an equidigital number, since it uses as much as digits as its factorization.

998164842721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13934592, while the sum is 61.

The spelling of 998164842721 in words is "nine hundred ninety-eight billion, one hundred sixty-four million, eight hundred forty-two thousand, seven hundred twenty-one".