640075867208 has 32 divisors (see below), whose sum is σ = 1227792081600. Its totient is φ = 312729609792.

The previous prime is 640075867201. The next prime is 640075867243. The reversal of 640075867208 is 802768570046.

It is a self number, because there is not a number n which added to its sum of digits gives 640075867208.

It is not an unprimeable number, because it can be changed into a prime (640075867201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3981335 + ... + 4138982.

It is an arithmetic number, because the mean of its divisors is an integer number (38368502550).

Almost surely, 2^640075867208 is an apocalyptic number.

It is an amenable number.

640075867208 is a deficient number, since it is larger than the sum of its proper divisors (587716214392).

640075867208 is a wasteful number, since it uses less digits than its factorization.

640075867208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8120549 (or 8120545 counting only the distinct ones).

The product of its (nonzero) digits is 4515840, while the sum is 53.

The spelling of 640075867208 in words is "six hundred forty billion, seventy-five million, eight hundred sixty-seven thousand, two hundred eight".