20309973 has 4 divisors (see below), whose sum is σ = 27079968. Its totient is φ = 13539980.

The previous prime is 20309959. The next prime is 20309999. The reversal of 20309973 is 37990302.

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 20309973 - 2⁵ = 20309941 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20309903) 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, 3384993 + ... + 3384998.

It is an arithmetic number, because the mean of its divisors is an integer number (6769992).

Almost surely, 2^20309973 is an apocalyptic number.

It is an amenable number.

20309973 is a deficient number, since it is larger than the sum of its proper divisors (6769995).

20309973 is an equidigital number, since it uses as much as digits as its factorization.

20309973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6769994.

The product of its (nonzero) digits is 10206, while the sum is 33.

The square root of 20309973 is about 4506.6587401311. The cubic root of 20309973 is about 272.8369056301.

The spelling of 20309973 in words is "twenty million, three hundred nine thousand, nine hundred seventy-three".