645522174 has 72 divisors (see below), whose sum is σ = 1543900176. Its totient is φ = 194779200.

The previous prime is 645522173. The next prime is 645522197. The reversal of 645522174 is 471225546.

It is a happy number.

645522174 is a `hidden beast` number, since 64 + 5 + 522 + 1 + 74 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645522173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 676882 + ... + 677834.

It is an arithmetic number, because the mean of its divisors is an integer number (21443058).

Almost surely, 2^645522174 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645522174, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (771950088).

645522174 is an abundant number, since it is smaller than the sum of its proper divisors (898378002).

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

645522174 is a wasteful number, since it uses less digits than its factorization.

645522174 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1294 (or 1280 counting only the distinct ones).

The product of its digits is 67200, while the sum is 36.

The square root of 645522174 is about 25407.1284091690. The cubic root of 645522174 is about 864.2453569507.

The spelling of 645522174 in words is "six hundred forty-five million, five hundred twenty-two thousand, one hundred seventy-four".