636353640 has 192 divisors, whose sum is σ = 2240784000. Its totient is φ = 155690496.

The previous prime is 636353609. The next prime is 636353657. The reversal of 636353640 is 46353636.

It is a happy number.

636353640 is a `hidden beast` number, since 6 + 3 + 6 + 3 + 5 + 3 + 640 = 666.

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 = 636353595 and 636353604.

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, 1062061 + ... + 1062659.

It is an arithmetic number, because the mean of its divisors is an integer number (11670750).

Almost surely, 2^636353640 is an apocalyptic number.

636353640 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 636353640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1120392000).

636353640 is an abundant number, since it is smaller than the sum of its proper divisors (1604430360).

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

636353640 is a wasteful number, since it uses less digits than its factorization.

636353640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856 (or 849 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 36.

The square root of 636353640 is about 25226.0508205307. The cubic root of 636353640 is about 860.1341236639.

The spelling of 636353640 in words is "six hundred thirty-six million, three hundred fifty-three thousand, six hundred forty".