645387783570 has 96 divisors (see below), whose sum is σ = 1703627976960. Its totient is φ = 169491168000.

The previous prime is 645387783541. The next prime is 645387783571. The reversal of 645387783570 is 75387783546.

645387783570 is a `hidden beast` number, since 6 + 4 + 53 + 8 + 7 + 7 + 8 + 3 + 570 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 645387783498 and 645387783507.

It is not an unprimeable number, because it can be changed into a prime (645387783571) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1850007 + ... + 2171013.

It is an arithmetic number, because the mean of its divisors is an integer number (17746124760).

Almost surely, 2^645387783570 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645387783570, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (851813988480).

645387783570 is an abundant number, since it is smaller than the sum of its proper divisors (1058240193390).

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

645387783570 is a wasteful number, since it uses less digits than its factorization.

645387783570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321360 (or 321357 counting only the distinct ones).

The product of its (nonzero) digits is 118540800, while the sum is 63.

The spelling of 645387783570 in words is "six hundred forty-five billion, three hundred eighty-seven million, seven hundred eighty-three thousand, five hundred seventy".