640094677 has 4 divisors (see below), whose sum is σ = 642372876. Its totient is φ = 637816480.

The previous prime is 640094657. The next prime is 640094701. The reversal of 640094677 is 776490046.

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

It can be written as a sum of positive squares in 2 ways, for example, as 237129201 + 402965476 = 15399^2 + 20074^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640094677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640094627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1138678 + ... + 1139239.

It is an arithmetic number, because the mean of its divisors is an integer number (160593219).

Almost surely, 2^640094677 is an apocalyptic number.

It is an amenable number.

640094677 is a deficient number, since it is larger than the sum of its proper divisors (2278199).

640094677 is a wasteful number, since it uses less digits than its factorization.

640094677 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2278198.

The product of its (nonzero) digits is 254016, while the sum is 43.

The square root of 640094677 is about 25300.0924306612. The cubic root of 640094677 is about 861.8163687952.

It can be divided in two parts, 64009 and 4677, that added together give a palindrome (68686).

The spelling of 640094677 in words is "six hundred forty million, ninety-four thousand, six hundred seventy-seven".