640323325620 has 72 divisors (see below), whose sum is σ = 2118888102240. Its totient is φ = 155229896640.

The previous prime is 640323325601. The next prime is 640323325661. The reversal of 640323325620 is 26523323046.

640323325620 is a `hidden beast` number, since 6 + 4 + 0 + 3 + 2 + 3 + 3 + 25 + 620 = 666.

640323325620 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×640323325620² (a number of 24 digits) contains 22 as substring.

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 23 ways as a sum of consecutive naturals, for example, 161695830 + ... + 161699789.

It is an arithmetic number, because the mean of its divisors is an integer number (29429001420).

Almost surely, 2^640323325620 is an apocalyptic number.

640323325620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

640323325620 is an abundant number, since it is smaller than the sum of its proper divisors (1478564776620).

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

640323325620 is a wasteful number, since it uses less digits than its factorization.

640323325620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323395645 (or 323395640 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 36.

Adding to 640323325620 its reverse (26523323046), we get a palindrome (666846648666).

The spelling of 640323325620 in words is "six hundred forty billion, three hundred twenty-three million, three hundred twenty-five thousand, six hundred twenty".