631198881 has 6 divisors (see below), whose sum is σ = 911731730. Its totient is φ = 420799248.

The previous prime is 631198879. The next prime is 631198921. The reversal of 631198881 is 188891136.

631198881 is a `hidden beast` number, since 631 + 1 + 9 + 8 + 8 + 8 + 1 = 666.

631198881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 628254225 + 2944656 = 25065^2 + 1716^2 .

It is not a de Polignac number, because 631198881 - 2¹ = 631198879 is a prime.

It is a super-2 number, since 2×631198881² = 796824054751304322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (631198811) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35066596 + ... + 35066613.

Almost surely, 2^631198881 is an apocalyptic number.

It is an amenable number.

631198881 is a deficient number, since it is larger than the sum of its proper divisors (280532849).

631198881 is a wasteful number, since it uses less digits than its factorization.

631198881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70133215 (or 70133212 counting only the distinct ones).

The product of its digits is 82944, while the sum is 45.

The square root of 631198881 is about 25123.6717260834. The cubic root of 631198881 is about 857.8053293656.

The spelling of 631198881 in words is "six hundred thirty-one million, one hundred ninety-eight thousand, eight hundred eighty-one".