63640400 has 60 divisors (see below), whose sum is σ = 153663900. Its totient is φ = 25328640.

The previous prime is 63640393. The next prime is 63640417. The reversal of 63640400 is 404636.

It can be written as a sum of positive squares in 6 ways, for example, as 87616 + 63552784 = 296^2 + 7972^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 155396 + ... + 155804.

It is an arithmetic number, because the mean of its divisors is an integer number (2561065).

Almost surely, 2^63640400 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 63640400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76831950).

63640400 is an abundant number, since it is smaller than the sum of its proper divisors (90023500).

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

63640400 is a wasteful number, since it uses less digits than its factorization.

63640400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 816 (or 805 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 63640400 is about 7977.4933406428. The cubic root of 63640400 is about 399.2494258102.

The spelling of 63640400 in words is "sixty-three million, six hundred forty thousand, four hundred".