640240297 has 8 divisors (see below), whose sum is σ = 656474112. Its totient is φ = 624036000.

The previous prime is 640240243. The next prime is 640240301. The reversal of 640240297 is 792042046.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640240297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640240217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40408 + ... + 53974.

It is an arithmetic number, because the mean of its divisors is an integer number (82059264).

Almost surely, 2^640240297 is an apocalyptic number.

It is an amenable number.

640240297 is a deficient number, since it is larger than the sum of its proper divisors (16233815).

640240297 is a wasteful number, since it uses less digits than its factorization.

640240297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14759.

The product of its (nonzero) digits is 24192, while the sum is 34.

The square root of 640240297 is about 25302.9701221023. The cubic root of 640240297 is about 861.8817175572.

The spelling of 640240297 in words is "six hundred forty million, two hundred forty thousand, two hundred ninety-seven".