636225408 has 576 divisors, whose sum is σ = 2498857200. Its totient is φ = 157925376.

The previous prime is 636225383. The next prime is 636225427. The reversal of 636225408 is 804522636.

It is a tau number, because it is divible by the number of its divisors (576).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 37425016 + ... + 37425032.

Almost surely, 2^636225408 is an apocalyptic number.

636225408 is a gapful number since it is divisible by the number (68) 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 636225408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1249428600).

636225408 is an abundant number, since it is smaller than the sum of its proper divisors (1862631792).

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

636225408 is a wasteful number, since it uses less digits than its factorization.

636225408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84 (or 42 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 636225408 is about 25223.5090342323. The cubic root of 636225408 is about 860.0763444033.

The spelling of 636225408 in words is "six hundred thirty-six million, two hundred twenty-five thousand, four hundred eight".