640464450545 has 8 divisors (see below), whose sum is σ = 768563425896. Its totient is φ = 512367503616.

The previous prime is 640464450539. The next prime is 640464450551. The reversal of 640464450545 is 545054464046.

It is an interprime number because it is at equal distance from previous prime (640464450539) and next prime (640464450551).

It can be written as a sum of positive squares in 4 ways, for example, as 62420525281 + 578043925264 = 249841^2 + 760292^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640464450545 - 2²⁴ = 640447673329 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 640464450545.

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, 306089 + ... + 1172441.

It is an arithmetic number, because the mean of its divisors is an integer number (96070428237).

Almost surely, 2^640464450545 is an apocalyptic number.

It is an amenable number.

640464450545 is a deficient number, since it is larger than the sum of its proper divisors (128098975351).

640464450545 is a wasteful number, since it uses less digits than its factorization.

640464450545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1014211.

The product of its (nonzero) digits is 4608000, while the sum is 47.

The spelling of 640464450545 in words is "six hundred forty billion, four hundred sixty-four million, four hundred fifty thousand, five hundred forty-five".