640148326818 has 96 divisors (see below), whose sum is σ = 1728444966912. Its totient is φ = 153482097600.

The previous prime is 640148326789. The next prime is 640148326823. The reversal of 640148326818 is 818623841046.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4021338 + ... + 4177493.

It is an arithmetic number, because the mean of its divisors is an integer number (18004635072).

Almost surely, 2^640148326818 is an apocalyptic number.

640148326818 is an abundant number, since it is smaller than the sum of its proper divisors (1088296640094).

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

640148326818 is a wasteful number, since it uses less digits than its factorization.

640148326818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8198880 (or 8198867 counting only the distinct ones).

The product of its (nonzero) digits is 1769472, while the sum is 51.

The spelling of 640148326818 in words is "six hundred forty billion, one hundred forty-eight million, three hundred twenty-six thousand, eight hundred eighteen".