640130400 has 432 divisors, whose sum is σ = 2781009504. Its totient is φ = 134922240.

The previous prime is 640130383. The next prime is 640130429. The reversal of 640130400 is 4031046.

It is a Harshad number since it is a multiple of its sum of digits (18).

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, 654712 + ... + 655688.

It is an arithmetic number, because the mean of its divisors is an integer number (6437522).

Almost surely, 2^640130400 is an apocalyptic number.

640130400 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 640130400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1390504752).

640130400 is an abundant number, since it is smaller than the sum of its proper divisors (2140879104).

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

640130400 is a wasteful number, since it uses less digits than its factorization.

640130400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1023 (or 1007 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 640130400 is about 25300.7984063745. The cubic root of 640130400 is about 861.8324008472.

Adding to 640130400 its reverse (4031046), we get a palindrome (644161446).

The spelling of 640130400 in words is "six hundred forty million, one hundred thirty thousand, four hundred".