645195264 has 160 divisors (see below), whose sum is σ = 2050583040. Its totient is φ = 176259072.

The previous prime is 645195251. The next prime is 645195301. The reversal of 645195264 is 462591546.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

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, 245992 + ... + 248600.

It is an arithmetic number, because the mean of its divisors is an integer number (12816144).

Almost surely, 2^645195264 is an apocalyptic number.

645195264 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645195264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1025291520).

645195264 is an abundant number, since it is smaller than the sum of its proper divisors (1405387776).

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

645195264 is a wasteful number, since it uses less digits than its factorization.

645195264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2660 (or 2644 counting only the distinct ones).

The product of its digits is 259200, while the sum is 42.

The square root of 645195264 is about 25400.6941637428. The cubic root of 645195264 is about 864.0994398579.

The spelling of 645195264 in words is "six hundred forty-five million, one hundred ninety-five thousand, two hundred sixty-four".