998979901 has 2 divisors, whose sum is σ = 998979902. Its totient is φ = 998979900.

The previous prime is 998979899. The next prime is 998979923. The reversal of 998979901 is 109979899.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 793774276 + 205205625 = 28174^2 + 14325^2 .

It is an emirp because it is prime and its reverse (109979899) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 998979901 - 2¹ = 998979899 is a prime.

Together with 998979899, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 998979901.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (998979941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499489950 + 499489951.

It is an arithmetic number, because the mean of its divisors is an integer number (499489951).

Almost surely, 2^998979901 is an apocalyptic number.

It is an amenable number.

998979901 is a deficient number, since it is larger than the sum of its proper divisors (1).

998979901 is an equidigital number, since it uses as much as digits as its factorization.

998979901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3306744, while the sum is 61.

The square root of 998979901 is about 31606.6433048497. The cubic root of 998979901 is about 999.6598513120.

The spelling of 998979901 in words is "nine hundred ninety-eight million, nine hundred seventy-nine thousand, nine hundred one".