645103840 has 96 divisors (see below), whose sum is σ = 1615541760. Its totient is φ = 242995200.

The previous prime is 645103813. The next prime is 645103841. The reversal of 645103840 is 48301546.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645103841) 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, 188545 + ... + 191935.

It is an arithmetic number, because the mean of its divisors is an integer number (16828560).

Almost surely, 2^645103840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645103840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (807770880).

645103840 is an abundant number, since it is smaller than the sum of its proper divisors (970437920).

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

645103840 is a wasteful number, since it uses less digits than its factorization.

645103840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3476 (or 3468 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 645103840 is about 25398.8944641297. The cubic root of 645103840 is about 864.0586237085.

The spelling of 645103840 in words is "six hundred forty-five million, one hundred three thousand, eight hundred forty".