20471345 has 4 divisors (see below), whose sum is σ = 24565620. Its totient is φ = 16377072.

The previous prime is 20471327. The next prime is 20471389. The reversal of 20471345 is 54317402.

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 13337104 + 7134241 = 3652^2 + 2671^2 .

It is a cyclic number.

It is not a de Polignac number, because 20471345 - 2⁸ = 20471089 is a prime.

It is a super-2 number, since 2×20471345² = 838151932218050, which contains 22 as substring.

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, 2047130 + ... + 2047139.

It is an arithmetic number, because the mean of its divisors is an integer number (6141405).

Almost surely, 2^20471345 is an apocalyptic number.

It is an amenable number.

20471345 is a deficient number, since it is larger than the sum of its proper divisors (4094275).

20471345 is an equidigital number, since it uses as much as digits as its factorization.

20471345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4094274.

The product of its (nonzero) digits is 3360, while the sum is 26.

The square root of 20471345 is about 4524.5270471067. The cubic root of 20471345 is about 273.5576047830.

Adding to 20471345 its reverse (54317402), we get a palindrome (74788747).

The spelling of 20471345 in words is "twenty million, four hundred seventy-one thousand, three hundred forty-five".