645532371 has 24 divisors (see below), whose sum is σ = 1018105920. Its totient is φ = 390884400.

The previous prime is 645532369. The next prime is 645532411. The reversal of 645532371 is 173235546.

645532371 is a `hidden beast` number, since 645 + 5 + 3 + 2 + 3 + 7 + 1 = 666.

645532371 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 645532371 - 2¹ = 645532369 is a prime.

It is a super-3 number, since 3×645532371³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (645532301) 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, 149440 + ... + 153698.

It is an arithmetic number, because the mean of its divisors is an integer number (42421080).

Almost surely, 2^645532371 is an apocalyptic number.

645532371 is a deficient number, since it is larger than the sum of its proper divisors (372573549).

645532371 is a wasteful number, since it uses less digits than its factorization.

645532371 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5807 (or 5804 counting only the distinct ones).

The product of its digits is 75600, while the sum is 36.

The square root of 645532371 is about 25407.3290804051. The cubic root of 645532371 is about 864.2499076146.

The spelling of 645532371 in words is "six hundred forty-five million, five hundred thirty-two thousand, three hundred seventy-one".