645754140 has 96 divisors (see below), whose sum is σ = 2114784000. Its totient is φ = 163135296.

The previous prime is 645754139. The next prime is 645754147. The reversal of 645754140 is 41457546.

645754140 is a `hidden beast` number, since 6 + 4 + 575 + 41 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 645754095 and 645754104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645754147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21210 + ... + 41729.

It is an arithmetic number, because the mean of its divisors is an integer number (22029000).

Almost surely, 2^645754140 is an apocalyptic number.

645754140 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

645754140 is an abundant number, since it is smaller than the sum of its proper divisors (1469029860).

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

645754140 is a wasteful number, since it uses less digits than its factorization.

645754140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62976 (or 62968 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 36.

The square root of 645754140 is about 25411.6929778399. The cubic root of 645754140 is about 864.3488656748.

The spelling of 645754140 in words is "six hundred forty-five million, seven hundred fifty-four thousand, one hundred forty".