20371993 has 2 divisors, whose sum is σ = 20371994. Its totient is φ = 20371992.

The previous prime is 20371969. The next prime is 20371999. The reversal of 20371993 is 39917302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16581184 + 3790809 = 4072^2 + 1947^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20371993 is a prime.

It is not a weakly prime, because it can be changed into another prime (20371999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10185996 + 10185997.

It is an arithmetic number, because the mean of its divisors is an integer number (10185997).

Almost surely, 2^20371993 is an apocalyptic number.

It is an amenable number.

20371993 is a deficient number, since it is larger than the sum of its proper divisors (1).

20371993 is an equidigital number, since it uses as much as digits as its factorization.

20371993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10206, while the sum is 34.

The square root of 20371993 is about 4513.5344243730. The cubic root of 20371993 is about 273.1143415802.

The spelling of 20371993 in words is "twenty million, three hundred seventy-one thousand, nine hundred ninety-three".