20945345 has 4 divisors (see below), whose sum is σ = 25134420. Its totient is φ = 16756272.

The previous prime is 20945321. The next prime is 20945363. The reversal of 20945345 is 54354902.

It is a happy number.

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 13366336 + 7579009 = 3656^2 + 2753^2 .

It is a cyclic number.

It is not a de Polignac number, because 20945345 - 2¹⁴ = 20928961 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2094530 + ... + 2094539.

It is an arithmetic number, because the mean of its divisors is an integer number (6283605).

Almost surely, 2^20945345 is an apocalyptic number.

It is an amenable number.

20945345 is a deficient number, since it is larger than the sum of its proper divisors (4189075).

20945345 is an equidigital number, since it uses as much as digits as its factorization.

20945345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4189074.

The product of its (nonzero) digits is 21600, while the sum is 32.

The square root of 20945345 is about 4576.6084604213. The cubic root of 20945345 is about 275.6528620734.

It can be divided in two parts, 209 and 45345, that added together give a palindrome (45554).

The spelling of 20945345 in words is "twenty million, nine hundred forty-five thousand, three hundred forty-five".