645053544 has 80 divisors (see below), whose sum is σ = 1810462500. Its totient is φ = 214576128.

The previous prime is 645053543. The next prime is 645053551. The reversal of 645053544 is 445350546.

645053544 is a `hidden beast` number, since 64 + 5 + 0 + 53 + 544 = 666.

645053544 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 643231044 + 1822500 = 25362^2 + 1350^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 645053499 and 645053508.

It is not an unprimeable number, because it can be changed into a prime (645053543) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 515832 + ... + 517080.

Almost surely, 2^645053544 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 645053544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (905231250).

645053544 is an abundant number, since it is smaller than the sum of its proper divisors (1165408956).

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

645053544 is a wasteful number, since it uses less digits than its factorization.

645053544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2064 (or 2051 counting only the distinct ones).

The product of its (nonzero) digits is 144000, while the sum is 36.

The square root of 645053544 is about 25397.9043229948. The cubic root of 645053544 is about 864.0361674675.

The spelling of 645053544 in words is "six hundred forty-five million, fifty-three thousand, five hundred forty-four".