640222998 has 16 divisors (see below), whose sum is σ = 1280862720. Its totient is φ = 213338216.

The previous prime is 640222997. The next prime is 640223021. The reversal of 640222998 is 899222046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640222997) 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, 4783 + ... + 36101.

It is an arithmetic number, because the mean of its divisors is an integer number (80053920).

Almost surely, 2^640222998 is an apocalyptic number.

640222998 is an abundant number, since it is smaller than the sum of its proper divisors (640639722).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640222998 is a wasteful number, since it uses less digits than its factorization.

640222998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34731.

The product of its (nonzero) digits is 124416, while the sum is 42.

The square root of 640222998 is about 25302.6282824532. The cubic root of 640222998 is about 861.8739549373.

The spelling of 640222998 in words is "six hundred forty million, two hundred twenty-two thousand, nine hundred ninety-eight".