20447071 has 4 divisors (see below), whose sum is σ = 20494944. Its totient is φ = 20399200.

The previous prime is 20447057. The next prime is 20447083. The reversal of 20447071 is 17074402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17074402 = 2 ⋅8537201.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20447071 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20447671) 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, 23290 + ... + 24151.

It is an arithmetic number, because the mean of its divisors is an integer number (5123736).

Almost surely, 2^20447071 is an apocalyptic number.

20447071 is a deficient number, since it is larger than the sum of its proper divisors (47873).

20447071 is an equidigital number, since it uses as much as digits as its factorization.

20447071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47872.

The product of its (nonzero) digits is 1568, while the sum is 25.

The square root of 20447071 is about 4521.8437611222. The cubic root of 20447071 is about 273.4494379180.

The spelling of 20447071 in words is "twenty million, four hundred forty-seven thousand, seventy-one".