645571510272 has 768 divisors, whose sum is σ = 2168726162400. Its totient is φ = 188554936320.

The previous prime is 645571510261. The next prime is 645571510301. The reversal of 645571510272 is 272015175546.

645571510272 is a `hidden beast` number, since 6 + 4 + 5 + 571 + 5 + 1 + 0 + 2 + 72 = 666.

It is a tau number, because it is divible by the number of its divisors (768).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15745646572 + ... + 15745646612.

Almost surely, 2^645571510272 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 645571510272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1084363081200).

645571510272 is an abundant number, since it is smaller than the sum of its proper divisors (1523154652128).

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

645571510272 is an equidigital number, since it uses as much as digits as its factorization.

645571510272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 588000, while the sum is 45.

The spelling of 645571510272 in words is "six hundred forty-five billion, five hundred seventy-one million, five hundred ten thousand, two hundred seventy-two".