640340775274 has 4 divisors (see below), whose sum is σ = 960511162914. Its totient is φ = 320170387636.

The previous prime is 640340775257. The next prime is 640340775337. The reversal of 640340775274 is 472577043046.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 603224055625 + 37116719649 = 776675^2 + 192657^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160085193817 + ... + 160085193820.

Almost surely, 2^640340775274 is an apocalyptic number.

640340775274 is a deficient number, since it is larger than the sum of its proper divisors (320170387640).

640340775274 is a wasteful number, since it uses less digits than its factorization.

640340775274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320170387639.

The product of its (nonzero) digits is 3951360, while the sum is 49.

The spelling of 640340775274 in words is "six hundred forty billion, three hundred forty million, seven hundred seventy-five thousand, two hundred seventy-four".