631493640 has 96 divisors (see below), whose sum is σ = 2060299800. Its totient is φ = 167746560.

The previous prime is 631493623. The next prime is 631493641. The reversal of 631493640 is 46394136.

631493640 is a `hidden beast` number, since 6 + 3 + 1 + 4 + 9 + 3 + 640 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 501670404 + 129823236 = 22398^2 + 11394^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 631493595 and 631493604.

It is not an unprimeable number, because it can be changed into a prime (631493641) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 93580 + ... + 100100.

Almost surely, 2^631493640 is an apocalyptic number.

631493640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 631493640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1030149900).

631493640 is an abundant number, since it is smaller than the sum of its proper divisors (1428806160).

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

631493640 is a wasteful number, since it uses less digits than its factorization.

631493640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6807 (or 6800 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 36.

The square root of 631493640 is about 25129.5372022646. The cubic root of 631493640 is about 857.9388353549.

The spelling of 631493640 in words is "six hundred thirty-one million, four hundred ninety-three thousand, six hundred forty".