640434711227726 has 32 divisors (see below), whose sum is σ = 987370868452320. Its totient is φ = 311324395954176.

The previous prime is 640434711227719. The next prime is 640434711227737. The reversal of 640434711227726 is 627722117434046.

It is a super-2 number, since 2×640434711227726² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 804944606 + ... + 805739838.

It is an arithmetic number, because the mean of its divisors is an integer number (30855339639135).

Almost surely, 2^{640434711227726} is an apocalyptic number.

640434711227726 is a deficient number, since it is larger than the sum of its proper divisors (346936157224594).

640434711227726 is a wasteful number, since it uses less digits than its factorization.

640434711227726 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 803588.

The product of its (nonzero) digits is 18966528, while the sum is 56.

The spelling of 640434711227726 in words is "six hundred forty trillion, four hundred thirty-four billion, seven hundred eleven million, two hundred twenty-seven thousand, seven hundred twenty-six".