631778994 has 192 divisors, whose sum is σ = 1859020800. Its totient is φ = 155247840.

The previous prime is 631778993. The next prime is 631779059. The reversal of 631778994 is 499877136.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 631778994.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631778993) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 868659 + ... + 869385.

It is an arithmetic number, because the mean of its divisors is an integer number (9682400).

Almost surely, 2^631778994 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 631778994, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (929510400).

631778994 is an abundant number, since it is smaller than the sum of its proper divisors (1227241806).

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

631778994 is a wasteful number, since it uses less digits than its factorization.

631778994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 786 (or 769 counting only the distinct ones).

The product of its digits is 2286144, while the sum is 54.

The square root of 631778994 is about 25135.2142222819. The cubic root of 631778994 is about 858.0680419412.

631778994 divided by its sum of digits (54) gives a palindrome (11699611).

The spelling of 631778994 in words is "six hundred thirty-one million, seven hundred seventy-eight thousand, nine hundred ninety-four".