631781642 has 8 divisors (see below), whose sum is σ = 1003417956. Its totient is φ = 297308992.

The previous prime is 631781629. The next prime is 631781699. The reversal of 631781642 is 246187136.

It can be written as a sum of positive squares in 2 ways, for example, as 622053481 + 9728161 = 24941^2 + 3119^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 631781596 and 631781605.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9290873 + ... + 9290940.

Almost surely, 2^631781642 is an apocalyptic number.

631781642 is a deficient number, since it is larger than the sum of its proper divisors (371636314).

631781642 is a wasteful number, since it uses less digits than its factorization.

631781642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18581832.

The product of its digits is 48384, while the sum is 38.

The square root of 631781642 is about 25135.2668973297. The cubic root of 631781642 is about 858.0692407576.

The spelling of 631781642 in words is "six hundred thirty-one million, seven hundred eighty-one thousand, six hundred forty-two".