1645185872 has 120 divisors (see below), whose sum is σ = 3670318656. Its totient is φ = 708288000.

The previous prime is 1645185859. The next prime is 1645185907. The reversal of 1645185872 is 2785815461.

It is a congruent number.

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 23 ways as a sum of consecutive naturals, for example, 12008588 + ... + 12008724.

Almost surely, 2^1645185872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1645185872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1835159328).

1645185872 is an abundant number, since it is smaller than the sum of its proper divisors (2025132784).

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

1645185872 is a wasteful number, since it uses less digits than its factorization.

1645185872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289 (or 252 counting only the distinct ones).

The product of its digits is 537600, while the sum is 47.

The square root of 1645185872 is about 40560.8909172370. The cubic root of 1645185872 is about 1180.5154006285.

The spelling of 1645185872 in words is "one billion, six hundred forty-five million, one hundred eighty-five thousand, eight hundred seventy-two".