640537336 has 16 divisors (see below), whose sum is σ = 1211637600. Its totient is φ = 317433984.

The previous prime is 640537279. The next prime is 640537343. The reversal of 640537336 is 633735046.

It is a junction number, because it is equal to n+sod(n) for n = 640537295 and 640537304.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 353376 + ... + 355183.

It is an arithmetic number, because the mean of its divisors is an integer number (75727350).

Almost surely, 2^640537336 is an apocalyptic number.

It is an amenable number.

640537336 is a deficient number, since it is larger than the sum of its proper divisors (571100264).

640537336 is a wasteful number, since it uses less digits than its factorization.

640537336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 708678 (or 708674 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 37.

The square root of 640537336 is about 25308.8390883501. The cubic root of 640537336 is about 862.0149867389.

The spelling of 640537336 in words is "six hundred forty million, five hundred thirty-seven thousand, three hundred thirty-six".