640787613 has 64 divisors (see below), whose sum is σ = 985374720. Its totient is φ = 368141312.

The previous prime is 640787611. The next prime is 640787627. The reversal of 640787613 is 316787046.

It is not a de Polignac number, because 640787613 - 2¹ = 640787611 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640787611) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3252631 + ... + 3252827.

It is an arithmetic number, because the mean of its divisors is an integer number (15396480).

Almost surely, 2^640787613 is an apocalyptic number.

It is an amenable number.

640787613 is a deficient number, since it is larger than the sum of its proper divisors (344587107).

640787613 is a wasteful number, since it uses less digits than its factorization.

640787613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346.

The product of its (nonzero) digits is 169344, while the sum is 42.

The square root of 640787613 is about 25313.7830637777. The cubic root of 640787613 is about 862.1272437559.

The spelling of 640787613 in words is "six hundred forty million, seven hundred eighty-seven thousand, six hundred thirteen".