645096672 has 144 divisors (see below), whose sum is σ = 2015565552. Its totient is φ = 194088960.

The previous prime is 645096649. The next prime is 645096679. The reversal of 645096672 is 276690546.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×645096672² = 832299432450951168, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645096679) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 496728 + ... + 498024.

It is an arithmetic number, because the mean of its divisors is an integer number (13996983).

Almost surely, 2^645096672 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 645096672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1007782776).

645096672 is an abundant number, since it is smaller than the sum of its proper divisors (1370468880).

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

645096672 is a wasteful number, since it uses less digits than its factorization.

645096672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1481 (or 1470 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The square root of 645096672 is about 25398.7533552338. The cubic root of 645096672 is about 864.0554233994.

The spelling of 645096672 in words is "six hundred forty-five million, ninety-six thousand, six hundred seventy-two".