631428381 has 6 divisors (see below), whose sum is σ = 912063230. Its totient is φ = 420952248.

The previous prime is 631428377. The next prime is 631428403. The reversal of 631428381 is 183824136.

631428381 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., 565964100 + 65464281 = 23790^2 + 8091^2 .

It is not a de Polignac number, because 631428381 - 2² = 631428377 is a prime.

It is a super-2 number, since 2×631428381² = 797403600664562322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631421381) 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, 35079346 + ... + 35079363.

Almost surely, 2^631428381 is an apocalyptic number.

It is an amenable number.

631428381 is a deficient number, since it is larger than the sum of its proper divisors (280634849).

631428381 is a wasteful number, since it uses less digits than its factorization.

631428381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70158715 (or 70158712 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 631428381 is about 25128.2387166311. The cubic root of 631428381 is about 857.9092810012.

The spelling of 631428381 in words is "six hundred thirty-one million, four hundred twenty-eight thousand, three hundred eighty-one".