640209617162 has 32 divisors (see below), whose sum is σ = 996724056720. Its totient is φ = 308153548800.

The previous prime is 640209617147. The next prime is 640209617189. The reversal of 640209617162 is 261716902046.

It is a Cunningham number, because it is equal to 800131²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 573744136681 + 66465480481 = 757459^2 + 257809^2 .

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, 29627162 + ... + 29648762.

Almost surely, 2^640209617162 is an apocalyptic number.

640209617162 is a deficient number, since it is larger than the sum of its proper divisors (356514439558).

640209617162 is a wasteful number, since it uses less digits than its factorization.

640209617162 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25866.

The product of its (nonzero) digits is 217728, while the sum is 44.

The spelling of 640209617162 in words is "six hundred forty billion, two hundred nine million, six hundred seventeen thousand, one hundred sixty-two".