645820084 has 48 divisors (see below), whose sum is σ = 1393531776. Its totient is φ = 255024000.

The previous prime is 645820079. The next prime is 645820103. The reversal of 645820084 is 480028546.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 253899 + ... + 256429.

It is an arithmetic number, because the mean of its divisors is an integer number (29031912).

Almost surely, 2^645820084 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 645820084, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (696765888).

645820084 is an abundant number, since it is smaller than the sum of its proper divisors (747711692).

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

645820084 is a wasteful number, since it uses less digits than its factorization.

645820084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3256 (or 3254 counting only the distinct ones).

The product of its (nonzero) digits is 61440, while the sum is 37.

The square root of 645820084 is about 25412.9904576380. The cubic root of 645820084 is about 864.3782869245.

The spelling of 645820084 in words is "six hundred forty-five million, eight hundred twenty thousand, eighty-four".