20497993 has 2 divisors, whose sum is σ = 20497994. Its totient is φ = 20497992.

The previous prime is 20497921. The next prime is 20497999. The reversal of 20497993 is 39979402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12730624 + 7767369 = 3568^2 + 2787^2 .

It is a cyclic number.

It is not a de Polignac number, because 20497993 - 2⁹ = 20497481 is a prime.

It is not a weakly prime, because it can be changed into another prime (20497999) 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 as a sum of consecutive naturals, namely, 10248996 + 10248997.

It is an arithmetic number, because the mean of its divisors is an integer number (10248997).

Almost surely, 2^20497993 is an apocalyptic number.

It is an amenable number.

20497993 is a deficient number, since it is larger than the sum of its proper divisors (1).

20497993 is an equidigital number, since it uses as much as digits as its factorization.

20497993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 122472, while the sum is 43.

The square root of 20497993 is about 4527.4709275709. The cubic root of 20497993 is about 273.6762519661.

The spelling of 20497993 in words is "twenty million, four hundred ninety-seven thousand, nine hundred ninety-three".