631906985 has 8 divisors (see below), whose sum is σ = 766106376. Its totient is φ = 500313600.

The previous prime is 631906967. The next prime is 631906987. The reversal of 631906985 is 589609136.

It can be written as a sum of positive squares in 4 ways, for example, as 49505296 + 582401689 = 7036^2 + 24133^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 631906985 - 2¹⁰ = 631905961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (631906987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 650966 + ... + 651935.

It is an arithmetic number, because the mean of its divisors is an integer number (95763297).

Almost surely, 2^631906985 is an apocalyptic number.

It is an amenable number.

631906985 is a deficient number, since it is larger than the sum of its proper divisors (134199391).

631906985 is a wasteful number, since it uses less digits than its factorization.

631906985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1303003.

The product of its (nonzero) digits is 349920, while the sum is 47.

The square root of 631906985 is about 25137.7601428608. The cubic root of 631906985 is about 858.1259828626.

The spelling of 631906985 in words is "six hundred thirty-one million, nine hundred six thousand, nine hundred eighty-five".