636478794 has 96 divisors (see below), whose sum is σ = 1661976576. Its totient is φ = 172190880.

The previous prime is 636478781. The next prime is 636478849. The reversal of 636478794 is 497874636.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 636478794.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 181849 + ... + 185315.

It is an arithmetic number, because the mean of its divisors is an integer number (17312256).

Almost surely, 2^636478794 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 636478794, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (830988288).

636478794 is an abundant number, since it is smaller than the sum of its proper divisors (1025497782).

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

636478794 is a wasteful number, since it uses less digits than its factorization.

636478794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3560 (or 3557 counting only the distinct ones).

The product of its digits is 6096384, while the sum is 54.

The square root of 636478794 is about 25228.5313484555. The cubic root of 636478794 is about 860.1905085433.

It can be divided in two parts, 6364 and 78794, that added together give a palindrome (85158).

The spelling of 636478794 in words is "six hundred thirty-six million, four hundred seventy-eight thousand, seven hundred ninety-four".