645855180 has 48 divisors (see below), whose sum is σ = 1887024384. Its totient is φ = 164739520.

The previous prime is 645855173. The next prime is 645855187. The reversal of 645855180 is 81558546.

It is an interprime number because it is at equal distance from previous prime (645855173) and next prime (645855187).

It is not an unprimeable number, because it can be changed into a prime (645855187) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 232626 + ... + 235385.

It is an arithmetic number, because the mean of its divisors is an integer number (39313008).

Almost surely, 2^645855180 is an apocalyptic number.

645855180 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

645855180 is an abundant number, since it is smaller than the sum of its proper divisors (1241169204).

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

645855180 is a wasteful number, since it uses less digits than its factorization.

645855180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 468046 (or 468044 counting only the distinct ones).

The product of its (nonzero) digits is 192000, while the sum is 42.

The square root of 645855180 is about 25413.6809612461. The cubic root of 645855180 is about 864.3939443662.

The spelling of 645855180 in words is "six hundred forty-five million, eight hundred fifty-five thousand, one hundred eighty".