645144642318 has 128 divisors (see below), whose sum is σ = 1452646379520. Its totient is φ = 189366912000.

The previous prime is 645144642293. The next prime is 645144642319. The reversal of 645144642318 is 813246441546.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645144642319) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 63176233 + ... + 63186443.

It is an arithmetic number, because the mean of its divisors is an integer number (11348799840).

Almost surely, 2^645144642318 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645144642318, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (726323189760).

645144642318 is an abundant number, since it is smaller than the sum of its proper divisors (807501737202).

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

645144642318 is a wasteful number, since it uses less digits than its factorization.

645144642318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10534.

The product of its digits is 2211840, while the sum is 48.

The spelling of 645144642318 in words is "six hundred forty-five billion, one hundred forty-four million, six hundred forty-two thousand, three hundred eighteen".