1645281233 has 4 divisors (see below), whose sum is σ = 1742062500. Its totient is φ = 1548499968.

The previous prime is 1645281223. The next prime is 1645281247. The reversal of 1645281233 is 3321825461.

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 729432064 + 915849169 = 27008^2 + 30263^2 .

It is a cyclic number.

It is not a de Polignac number, because 1645281233 - 2⁴ = 1645281217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1645281193 and 1645281202.

It is not an unprimeable number, because it can be changed into a prime (1645281223) 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, 48390608 + ... + 48390641.

It is an arithmetic number, because the mean of its divisors is an integer number (435515625).

Almost surely, 2^1645281233 is an apocalyptic number.

It is an amenable number.

1645281233 is a deficient number, since it is larger than the sum of its proper divisors (96781267).

1645281233 is an equidigital number, since it uses as much as digits as its factorization.

1645281233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96781266.

The product of its digits is 34560, while the sum is 35.

The square root of 1645281233 is about 40562.0664291158. The cubic root of 1645281233 is about 1180.5382091869.

The spelling of 1645281233 in words is "one billion, six hundred forty-five million, two hundred eighty-one thousand, two hundred thirty-three".