645615960 has 128 divisors (see below), whose sum is σ = 2170195200. Its totient is φ = 152271360.

The previous prime is 645615931. The next prime is 645615961. The reversal of 645615960 is 69516546.

645615960 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645615961) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 42231 + ... + 55449.

It is an arithmetic number, because the mean of its divisors is an integer number (16954650).

Almost surely, 2^645615960 is an apocalyptic number.

645615960 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645615960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1085097600).

645615960 is an abundant number, since it is smaller than the sum of its proper divisors (1524579240).

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

645615960 is a wasteful number, since it uses less digits than its factorization.

645615960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13281 (or 13277 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 42.

The square root of 645615960 is about 25408.9740052604. The cubic root of 645615960 is about 864.2872094711.

It can be divided in two parts, 645 and 615960, that added together give a triangular number (616605 = T₁₁₁₀).

The spelling of 645615960 in words is "six hundred forty-five million, six hundred fifteen thousand, nine hundred sixty".