640409730049 has 8 divisors (see below), whose sum is σ = 646661533320. Its totient is φ = 634180786176.

The previous prime is 640409730019. The next prime is 640409730109. The reversal of 640409730049 is 940037904046.

It can be written as a sum of positive squares in 4 ways, for example, as 238793482225 + 401616247824 = 488665^2 + 633732^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640409730049 - 2⁵ = 640409730017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 640409729990 and 640409730008.

It is not an unprimeable number, because it can be changed into a prime (640409730019) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5658544 + ... + 5770609.

It is an arithmetic number, because the mean of its divisors is an integer number (80832691665).

Almost surely, 2^640409730049 is an apocalyptic number.

It is an amenable number.

640409730049 is a deficient number, since it is larger than the sum of its proper divisors (6251803271).

640409730049 is a wasteful number, since it uses less digits than its factorization.

640409730049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11429699.

The product of its (nonzero) digits is 653184, while the sum is 46.

The spelling of 640409730049 in words is "six hundred forty billion, four hundred nine million, seven hundred thirty thousand, forty-nine".