20391073 has 4 divisors (see below), whose sum is σ = 20865328. Its totient is φ = 19916820.

The previous prime is 20391071. The next prime is 20391101. The reversal of 20391073 is 37019302.

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 20391073 - 2¹ = 20391071 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20391071) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 237063 + ... + 237148.

It is an arithmetic number, because the mean of its divisors is an integer number (5216332).

Almost surely, 2^20391073 is an apocalyptic number.

It is an amenable number.

20391073 is a deficient number, since it is larger than the sum of its proper divisors (474255).

20391073 is an equidigital number, since it uses as much as digits as its factorization.

20391073 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474254.

The product of its (nonzero) digits is 1134, while the sum is 25.

The square root of 20391073 is about 4515.6475726079. The cubic root of 20391073 is about 273.1995794464.

The spelling of 20391073 in words is "twenty million, three hundred ninety-one thousand, seventy-three".