645433753 has 4 divisors (see below), whose sum is σ = 645489280. Its totient is φ = 645378228.

The previous prime is 645433729. The next prime is 645433757. The reversal of 645433753 is 357334546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 357334546 = 2 ⋅178667273.

It is a cyclic number.

It is not a de Polignac number, because 645433753 - 2⁵ = 645433721 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (645433757) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2913 + ... + 36046.

It is an arithmetic number, because the mean of its divisors is an integer number (161372320).

Almost surely, 2^645433753 is an apocalyptic number.

It is an amenable number.

645433753 is a deficient number, since it is larger than the sum of its proper divisors (55527).

645433753 is a wasteful number, since it uses less digits than its factorization.

645433753 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55526.

The product of its digits is 453600, while the sum is 40.

The square root of 645433753 is about 25405.3882670586. The cubic root of 645433753 is about 864.2058948784.

The spelling of 645433753 in words is "six hundred forty-five million, four hundred thirty-three thousand, seven hundred fifty-three".