640456340 has 24 divisors (see below), whose sum is σ = 1353216480. Its totient is φ = 254609568.

The previous prime is 640456337. The next prime is 640456343. The reversal of 640456340 is 43654046.

It is an interprime number because it is at equal distance from previous prime (640456337) and next prime (640456343).

It is a junction number, because it is equal to n+sod(n) for n = 640456297 and 640456306.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640456343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94970 + ... + 101489.

It is an arithmetic number, because the mean of its divisors is an integer number (56384020).

Almost surely, 2^640456340 is an apocalyptic number.

It is an amenable number.

640456340 is an abundant number, since it is smaller than the sum of its proper divisors (712760140).

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

640456340 is a wasteful number, since it uses less digits than its factorization.

640456340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196631 (or 196629 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 32.

The square root of 640456340 is about 25307.2388853466. The cubic root of 640456340 is about 861.9786512514.

The spelling of 640456340 in words is "six hundred forty million, four hundred fifty-six thousand, three hundred forty".