631991887386 has 8 divisors (see below), whose sum is σ = 1263983774784. Its totient is φ = 210663962460.

The previous prime is 631991887337. The next prime is 631991887391. The reversal of 631991887386 is 683788199136.

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

631991887386 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 631991887386.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 52665990610 + ... + 52665990621.

It is an arithmetic number, because the mean of its divisors is an integer number (157997971848).

Almost surely, 2^631991887386 is an apocalyptic number.

631991887386 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

631991887386 is a wasteful number, since it uses less digits than its factorization.

631991887386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105331981236.

The product of its digits is 94058496, while the sum is 69.

The spelling of 631991887386 in words is "six hundred thirty-one billion, nine hundred ninety-one million, eight hundred eighty-seven thousand, three hundred eighty-six".