640195722 has 12 divisors (see below), whose sum is σ = 1387090770. Its totient is φ = 213398568.

The previous prime is 640195681. The next prime is 640195723. The reversal of 640195722 is 227591046.

640195722 is a `hidden beast` number, since 640 + 1 + 9 + 5 + 7 + 2 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 504496521 + 135699201 = 22461^2 + 11649^2 .

It is not an unprimeable number, because it can be changed into a prime (640195723) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17783197 + ... + 17783232.

Almost surely, 2^640195722 is an apocalyptic number.

640195722 is an abundant number, since it is smaller than the sum of its proper divisors (746895048).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640195722 is a wasteful number, since it uses less digits than its factorization.

640195722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35566437 (or 35566434 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 640195722 is about 25302.0892813222. The cubic root of 640195722 is about 861.8617150313.

The spelling of 640195722 in words is "six hundred forty million, one hundred ninety-five thousand, seven hundred twenty-two".