640098959 has 8 divisors (see below), whose sum is σ = 648085152. Its totient is φ = 632147040.

The previous prime is 640098919. The next prime is 640098971. The reversal of 640098959 is 959890046.

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 640098959 - 2⁸ = 640098703 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640098919) 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, 30089 + ... + 46749.

It is an arithmetic number, because the mean of its divisors is an integer number (81010644).

Almost surely, 2^640098959 is an apocalyptic number.

640098959 is a deficient number, since it is larger than the sum of its proper divisors (7986193).

640098959 is a wasteful number, since it uses less digits than its factorization.

640098959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17137.

The product of its (nonzero) digits is 699840, while the sum is 50.

The square root of 640098959 is about 25300.1770547164. The cubic root of 640098959 is about 861.8182905367.

The spelling of 640098959 in words is "six hundred forty million, ninety-eight thousand, nine hundred fifty-nine".