645188214 has 24 divisors (see below), whose sum is σ = 1418349240. Its totient is φ = 195511360.

The previous prime is 645188207. The next prime is 645188227. The reversal of 645188214 is 412881546.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 443619 + ... + 445070.

It is an arithmetic number, because the mean of its divisors is an integer number (59097885).

Almost surely, 2^645188214 is an apocalyptic number.

645188214 is an abundant number, since it is smaller than the sum of its proper divisors (773161026).

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

645188214 is a wasteful number, since it uses less digits than its factorization.

645188214 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 888716 (or 888705 counting only the distinct ones).

The product of its digits is 61440, while the sum is 39.

The square root of 645188214 is about 25400.5553876288. Note that the first 3 decimals coincide. The cubic root of 645188214 is about 864.0962925300.

The spelling of 645188214 in words is "six hundred forty-five million, one hundred eighty-eight thousand, two hundred fourteen".