20445973 has 2 divisors, whose sum is σ = 20445974. Its totient is φ = 20445972.

The previous prime is 20445961. The next prime is 20445979. The reversal of 20445973 is 37954402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20007729 + 438244 = 4473^2 + 662^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20445973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20445979) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10222986 + 10222987.

It is an arithmetic number, because the mean of its divisors is an integer number (10222987).

Almost surely, 2^20445973 is an apocalyptic number.

It is an amenable number.

20445973 is a deficient number, since it is larger than the sum of its proper divisors (1).

20445973 is an equidigital number, since it uses as much as digits as its factorization.

20445973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 20445973 is about 4521.7223488401. The cubic root of 20445973 is about 273.4445431198. Note that the first 3 decimals are identical.

The spelling of 20445973 in words is "twenty million, four hundred forty-five thousand, nine hundred seventy-three".