636402140 has 96 divisors (see below), whose sum is σ = 1551965184. Its totient is φ = 216642560.

The previous prime is 636402121. The next prime is 636402163. The reversal of 636402140 is 41204636.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 983297 + ... + 983943.

It is an arithmetic number, because the mean of its divisors is an integer number (16166304).

Almost surely, 2^636402140 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 636402140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (775982592).

636402140 is an abundant number, since it is smaller than the sum of its proper divisors (915563044).

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

636402140 is a wasteful number, since it uses less digits than its factorization.

636402140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 947 (or 945 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

The square root of 636402140 is about 25227.0121100379. The cubic root of 636402140 is about 860.1559749547.

Adding to 636402140 its reverse (41204636), we get a palindrome (677606776).

The spelling of 636402140 in words is "six hundred thirty-six million, four hundred two thousand, one hundred forty".