640540421132 has 24 divisors (see below), whose sum is σ = 1131550027776. Its totient is φ = 317241091728.

The previous prime is 640540421107. The next prime is 640540421137. The reversal of 640540421132 is 231124045046.

It is a super-2 number, since 2×640540421132² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (640540421137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3918713 + ... + 4078895.

It is an arithmetic number, because the mean of its divisors is an integer number (47147917824).

Almost surely, 2^640540421132 is an apocalyptic number.

It is an amenable number.

640540421132 is a deficient number, since it is larger than the sum of its proper divisors (491009606644).

640540421132 is a wasteful number, since it uses less digits than its factorization.

640540421132 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169637 (or 169635 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 32.

Adding to 640540421132 its reverse (231124045046), we get a palindrome (871664466178).

The spelling of 640540421132 in words is "six hundred forty billion, five hundred forty million, four hundred twenty-one thousand, one hundred thirty-two".