645511560 has 64 divisors (see below), whose sum is σ = 2020740480. Its totient is φ = 164651520.

The previous prime is 645511549. The next prime is 645511579. The reversal of 645511560 is 65115546.

645511560 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, 114181 + ... + 119700.

It is an arithmetic number, because the mean of its divisors is an integer number (31574070).

Almost surely, 2^645511560 is an apocalyptic number.

645511560 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

645511560 is an abundant number, since it is smaller than the sum of its proper divisors (1375228920).

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

645511560 is a wasteful number, since it uses less digits than its factorization.

645511560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 233918 (or 233914 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 33.

The square root of 645511560 is about 25406.9195299233. The cubic root of 645511560 is about 864.2406201392.

The spelling of 645511560 in words is "six hundred forty-five million, five hundred eleven thousand, five hundred sixty".