640219255 has 16 divisors (see below), whose sum is σ = 837335520. Its totient is φ = 467077248.

The previous prime is 640219253. The next prime is 640219367. The reversal of 640219255 is 552912046.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 640219255 - 2¹ = 640219253 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 640219255.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640219253) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53940 + ... + 64729.

It is an arithmetic number, because the mean of its divisors is an integer number (52333470).

Almost surely, 2^640219255 is an apocalyptic number.

640219255 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

640219255 is a deficient number, since it is larger than the sum of its proper divisors (197116265).

640219255 is a wasteful number, since it uses less digits than its factorization.

640219255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118770.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 640219255 is about 25302.5543176969. The cubic root of 640219255 is about 861.8722753139.

The spelling of 640219255 in words is "six hundred forty million, two hundred nineteen thousand, two hundred fifty-five".