908631989 has 2 divisors, whose sum is σ = 908631990. Its totient is φ = 908631988.

The previous prime is 908631967. The next prime is 908631991. The reversal of 908631989 is 989136809.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 860952964 + 47679025 = 29342^2 + 6905^2 .

It is a cyclic number.

It is not a de Polignac number, because 908631989 - 2⁸ = 908631733 is a prime.

It is a super-2 number, since 2×908631989² = 1651224182868192242, which contains 22 as substring.

Together with 908631991, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 908631989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (908681989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 454315994 + 454315995.

It is an arithmetic number, because the mean of its divisors is an integer number (454315995).

Almost surely, 2^908631989 is an apocalyptic number.

It is an amenable number.

908631989 is a deficient number, since it is larger than the sum of its proper divisors (1).

908631989 is an equidigital number, since it uses as much as digits as its factorization.

908631989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 839808, while the sum is 53.

The square root of 908631989 is about 30143.5231683358. The cubic root of 908631989 is about 968.5662699557.

The spelling of 908631989 in words is "nine hundred eight million, six hundred thirty-one thousand, nine hundred eighty-nine".