640305774 has 24 divisors (see below), whose sum is σ = 1421168112. Its totient is φ = 208229280.

The previous prime is 640305739. The next prime is 640305779. The reversal of 640305774 is 477503046.

640305774 is a `hidden beast` number, since 640 + 3 + 0 + 5 + 7 + 7 + 4 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640305779) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 433074 + ... + 434549.

It is an arithmetic number, because the mean of its divisors is an integer number (59215338).

Almost surely, 2^640305774 is an apocalyptic number.

640305774 is an abundant number, since it is smaller than the sum of its proper divisors (780862338).

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

640305774 is a wasteful number, since it uses less digits than its factorization.

640305774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 867672 (or 867669 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 36.

The square root of 640305774 is about 25304.2639489869. The cubic root of 640305774 is about 861.9110979350.

The spelling of 640305774 in words is "six hundred forty million, three hundred five thousand, seven hundred seventy-four".