631985983 has 2 divisors, whose sum is σ = 631985984. Its totient is φ = 631985982.

The previous prime is 631985971. The next prime is 631986029. The reversal of 631985983 is 389589136.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 631985983 - 2²⁵ = 598431551 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 631985983.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631985903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315992991 + 315992992.

It is an arithmetic number, because the mean of its divisors is an integer number (315992992).

Almost surely, 2^631985983 is an apocalyptic number.

631985983 is a deficient number, since it is larger than the sum of its proper divisors (1).

631985983 is an equidigital number, since it uses as much as digits as its factorization.

631985983 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1399680, while the sum is 52.

The square root of 631985983 is about 25139.3313952460. The cubic root of 631985983 is about 858.1617409796.

The spelling of 631985983 in words is "six hundred thirty-one million, nine hundred eighty-five thousand, nine hundred eighty-three".