636794887680 has 1600 divisors, whose sum is σ = 2731037202432. Its totient is φ = 138788536320.

The previous prime is 636794887669. The next prime is 636794887711. The reversal of 636794887680 is 86788497636.

636794887680 is a `hidden beast` number, since 6 + 3 + 6 + 79 + 488 + 76 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a junction number, because it is equal to n+sod(n) for n = 636794887599 and 636794887608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 3813142957 + ... + 3813143123.

Almost surely, 2^636794887680 is an apocalyptic number.

636794887680 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 636794887680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1365518601216).

636794887680 is an abundant number, since it is smaller than the sum of its proper divisors (2094242314752).

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

636794887680 is a wasteful number, since it uses less digits than its factorization.

636794887680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317 (or 292 counting only the distinct ones).

The product of its (nonzero) digits is 585252864, while the sum is 72.

The spelling of 636794887680 in words is "six hundred thirty-six billion, seven hundred ninety-four million, eight hundred eighty-seven thousand, six hundred eighty".