640113620 has 24 divisors (see below), whose sum is σ = 1346625000. Its totient is φ = 255590912.

The previous prime is 640113619. The next prime is 640113623. The reversal of 640113620 is 26311046.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 94984516 + 545129104 = 9746^2 + 23348^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640113623) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16745 + ... + 39504.

It is an arithmetic number, because the mean of its divisors is an integer number (56109375).

Almost surely, 2^640113620 is an apocalyptic number.

It is an amenable number.

640113620 is an abundant number, since it is smaller than the sum of its proper divisors (706511380).

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

640113620 is a wasteful number, since it uses less digits than its factorization.

640113620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56827 (or 56825 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 640113620 is about 25300.4667941127. The cubic root of 640113620 is about 861.8248702597.

Adding to 640113620 its reverse (26311046), we get a palindrome (666424666).

The spelling of 640113620 in words is "six hundred forty million, one hundred thirteen thousand, six hundred twenty".