645027090 has 128 divisors (see below), whose sum is σ = 1706158080. Its totient is φ = 155409408.

The previous prime is 645027041. The next prime is 645027161. The reversal of 645027090 is 90720546.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1469091 + ... + 1469529.

It is an arithmetic number, because the mean of its divisors is an integer number (13329360).

Almost surely, 2^645027090 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645027090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (853079040).

645027090 is an abundant number, since it is smaller than the sum of its proper divisors (1061130990).

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

645027090 is a wasteful number, since it uses less digits than its factorization.

645027090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 576.

The product of its (nonzero) digits is 15120, while the sum is 33.

The square root of 645027090 is about 25397.3835266549. The cubic root of 645027090 is about 864.0243557735.

The spelling of 645027090 in words is "six hundred forty-five million, twenty-seven thousand, ninety".