640256625545 has 16 divisors (see below), whose sum is σ = 771220531200. Its totient is φ = 510266291904.

The previous prime is 640256625511. The next prime is 640256625571. The reversal of 640256625545 is 545526652046.

It is a cyclic number.

It is not a de Polignac number, because 640256625545 - 2¹⁰ = 640256624521 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640256625493 and 640256625502.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1728044 + ... + 2065586.

It is an arithmetic number, because the mean of its divisors is an integer number (48201283200).

Almost surely, 2^640256625545 is an apocalyptic number.

It is an amenable number.

640256625545 is a deficient number, since it is larger than the sum of its proper divisors (130963905655).

640256625545 is a wasteful number, since it uses less digits than its factorization.

640256625545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338984.

The product of its (nonzero) digits is 8640000, while the sum is 50.

The spelling of 640256625545 in words is "six hundred forty billion, two hundred fifty-six million, six hundred twenty-five thousand, five hundred forty-five".