640660120136 has 32 divisors (see below), whose sum is σ = 1274710651200. Its totient is φ = 301209395520.

The previous prime is 640660120099. The next prime is 640660120183. The reversal of 640660120136 is 631021066046.

It is a junction number, because it is equal to n+sod(n) for n = 640660120096 and 640660120105.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29496335 + ... + 29518046.

It is an arithmetic number, because the mean of its divisors is an integer number (39834707850).

Almost surely, 2^640660120136 is an apocalyptic number.

It is an amenable number.

640660120136 is a deficient number, since it is larger than the sum of its proper divisors (634050531064).

640660120136 is a wasteful number, since it uses less digits than its factorization.

640660120136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59014469 (or 59014465 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 35.

The spelling of 640660120136 in words is "six hundred forty billion, six hundred sixty million, one hundred twenty thousand, one hundred thirty-six".