631531404 has 90 divisors (see below), whose sum is σ = 1920538620. Its totient is φ = 180433008.

The previous prime is 631531399. The next prime is 631531409. The reversal of 631531404 is 404135136.

It is an interprime number because it is at equal distance from previous prime (631531399) and next prime (631531409).

It is a super-2 number, since 2×631531404² = 797663828476422432, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (631531409) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 4014 + ... + 35765.

It is an arithmetic number, because the mean of its divisors is an integer number (21339318).

Almost surely, 2^631531404 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 631531404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (960269310).

631531404 is an abundant number, since it is smaller than the sum of its proper divisors (1289007216).

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

631531404 is a wasteful number, since it uses less digits than its factorization.

631531404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39809 (or 39791 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 631531404 is about 25130.2885777303. The cubic root of 631531404 is about 857.9559369029.

The spelling of 631531404 in words is "six hundred thirty-one million, five hundred thirty-one thousand, four hundred four".