645433733 has 32 divisors (see below), whose sum is σ = 785971200. Its totient is φ = 529200000.

The previous prime is 645433729. The next prime is 645433757. The reversal of 645433733 is 337334546.

It is not a de Polignac number, because 645433733 - 2² = 645433729 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645433703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1073633 + ... + 1074233.

It is an arithmetic number, because the mean of its divisors is an integer number (24561600).

Almost surely, 2^645433733 is an apocalyptic number.

It is an amenable number.

645433733 is a deficient number, since it is larger than the sum of its proper divisors (140537467).

645433733 is a wasteful number, since it uses less digits than its factorization.

645433733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 754 (or 740 counting only the distinct ones).

The product of its digits is 272160, while the sum is 38.

The square root of 645433733 is about 25405.3878734413. The cubic root of 645433733 is about 864.2058859520.

The spelling of 645433733 in words is "six hundred forty-five million, four hundred thirty-three thousand, seven hundred thirty-three".