640326446423440 has 160 divisors (see below), whose sum is σ = 1879850589719040. Its totient is φ = 197642594721792.

The previous prime is 640326446423407. The next prime is 640326446423449. The reversal of 640326446423440 is 44324644623046.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (640326446423449) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1461980635 + ... + 1462418554.

It is an arithmetic number, because the mean of its divisors is an integer number (11749066185744).

Almost surely, 2^{640326446423440} is an apocalyptic number.

It is an amenable number.

640326446423440 is an abundant number, since it is smaller than the sum of its proper divisors (1239524143295600).

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

640326446423440 is a wasteful number, since it uses less digits than its factorization.

640326446423440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2924399249 (or 2924399243 counting only the distinct ones).

The product of its (nonzero) digits is 31850496, while the sum is 52.

The spelling of 640326446423440 in words is "six hundred forty trillion, three hundred twenty-six billion, four hundred forty-six million, four hundred twenty-three thousand, four hundred forty".