645768424 has 64 divisors (see below), whose sum is σ = 1454745600. Its totient is φ = 262747584.

The previous prime is 645768421. The next prime is 645768481. The reversal of 645768424 is 424867546.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is not an unprimeable number, because it can be changed into a prime (645768421) 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, 177229 + ... + 180835.

It is an arithmetic number, because the mean of its divisors is an integer number (22730400).

Almost surely, 2^645768424 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 645768424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (727372800).

645768424 is an abundant number, since it is smaller than the sum of its proper divisors (808977176).

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

645768424 is a wasteful number, since it uses less digits than its factorization.

645768424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3782 (or 3778 counting only the distinct ones).

The product of its digits is 1290240, while the sum is 46.

The square root of 645768424 is about 25411.9740280050. The cubic root of 645768424 is about 864.3552387237.

The spelling of 645768424 in words is "six hundred forty-five million, seven hundred sixty-eight thousand, four hundred twenty-four".