645273353 has 4 divisors (see below), whose sum is σ = 654112788. Its totient is φ = 636433920.

The previous prime is 645273337. The next prime is 645273371. The reversal of 645273353 is 353372546.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 497602249 + 147671104 = 22307^2 + 12152^2 .

It is a cyclic number.

It is not a de Polignac number, because 645273353 - 2⁴ = 645273337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645273373) 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, 4419608 + ... + 4419753.

It is an arithmetic number, because the mean of its divisors is an integer number (163528197).

Almost surely, 2^645273353 is an apocalyptic number.

It is an amenable number.

645273353 is a deficient number, since it is larger than the sum of its proper divisors (8839435).

645273353 is an equidigital number, since it uses as much as digits as its factorization.

645273353 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8839434.

The product of its digits is 226800, while the sum is 38.

The square root of 645273353 is about 25402.2312602653. The cubic root of 645273353 is about 864.1342995574.

The spelling of 645273353 in words is "six hundred forty-five million, two hundred seventy-three thousand, three hundred fifty-three".