645544140 has 48 divisors (see below), whose sum is σ = 1823538528. Its totient is φ = 170619904.

The previous prime is 645544127. The next prime is 645544153. The reversal of 645544140 is 41445546.

645544140 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (645544127) and next prime (645544153).

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, 40827 + ... + 54386.

It is an arithmetic number, because the mean of its divisors is an integer number (37990386).

Almost surely, 2^645544140 is an apocalyptic number.

645544140 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

645544140 is an abundant number, since it is smaller than the sum of its proper divisors (1177994388).

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

645544140 is a wasteful number, since it uses less digits than its factorization.

645544140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95338 (or 95336 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 33.

The square root of 645544140 is about 25407.5606857486. The cubic root of 645544140 is about 864.2551597630.

Adding to 645544140 its reverse (41445546), we get a palindrome (686989686).

The spelling of 645544140 in words is "six hundred forty-five million, five hundred forty-four thousand, one hundred forty".