20451071 has 4 divisors (see below), whose sum is σ = 21340272. Its totient is φ = 19561872.

The previous prime is 20451059. The next prime is 20451073. The reversal of 20451071 is 17015402.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20451071 - 2⁶ = 20451007 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 (20451073) 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, 444566 + ... + 444611.

It is an arithmetic number, because the mean of its divisors is an integer number (5335068).

Almost surely, 2^20451071 is an apocalyptic number.

20451071 is a deficient number, since it is larger than the sum of its proper divisors (889201).

20451071 is an equidigital number, since it uses as much as digits as its factorization.

20451071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 889200.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 20451071 is about 4522.2860369508. The cubic root of 20451071 is about 273.4672681235.

Adding to 20451071 its reverse (17015402), we get a palindrome (37466473).

The spelling of 20451071 in words is "twenty million, four hundred fifty-one thousand, seventy-one".