2145345221 has 4 divisors (see below), whose sum is σ = 2190990912. Its totient is φ = 2099699532.

The previous prime is 2145345203. The next prime is 2145345227. The reversal of 2145345221 is 1225435412.

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.

It is a cyclic number.

It is not a de Polignac number, because 2145345221 - 2¹⁴ = 2145328837 is a prime.

It is a super-2 number, since 2×2145345221² = 9205012234535077682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2145345227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22822775 + ... + 22822868.

It is an arithmetic number, because the mean of its divisors is an integer number (547747728).

Almost surely, 2^2145345221 is an apocalyptic number.

It is an amenable number.

2145345221 is a deficient number, since it is larger than the sum of its proper divisors (45645691).

2145345221 is an equidigital number, since it uses as much as digits as its factorization.

2145345221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45645690.

The product of its digits is 9600, while the sum is 29.

The square root of 2145345221 is about 46317.8715076589. The cubic root of 2145345221 is about 1289.7307734933.

It can be divided in two parts, 214 and 5345221, that added together give a palindrome (5345435).

The spelling of 2145345221 in words is "two billion, one hundred forty-five million, three hundred forty-five thousand, two hundred twenty-one".