640427341003656 has 32 divisors (see below), whose sum is σ = 1601069066345760. Its totient is φ = 213475685156352.

The previous prime is 640427341003633. The next prime is 640427341003699. The reversal of 640427341003656 is 656300143724046.

It is a junction number, because it is equal to n+sod(n) for n = 640427341003599 and 640427341003608.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67520811 + ... + 76419333.

It is an arithmetic number, because the mean of its divisors is an integer number (50033408323305).

Almost surely, 2^{640427341003656} is an apocalyptic number.

It is an amenable number.

640427341003656 is an abundant number, since it is smaller than the sum of its proper divisors (960641725342104).

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

640427341003656 is a wasteful number, since it uses less digits than its factorization.

640427341003656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11897285 (or 11897281 counting only the distinct ones).

The product of its (nonzero) digits is 8709120, while the sum is 51.

The spelling of 640427341003656 in words is "six hundred forty trillion, four hundred twenty-seven billion, three hundred forty-one million, three thousand, six hundred fifty-six".