20813393 has 2 divisors, whose sum is σ = 20813394. Its totient is φ = 20813392.

The previous prime is 20813347. The next prime is 20813399. The reversal of 20813393 is 39331802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20367169 + 446224 = 4513^2 + 668^2 .

It is a cyclic number.

It is not a de Polignac number, because 20813393 - 2²⁴ = 4036177 is a prime.

It is not a weakly prime, because it can be changed into another prime (20813399) 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, 10406696 + 10406697.

It is an arithmetic number, because the mean of its divisors is an integer number (10406697).

Almost surely, 2^20813393 is an apocalyptic number.

It is an amenable number.

20813393 is a deficient number, since it is larger than the sum of its proper divisors (1).

20813393 is an equidigital number, since it uses as much as digits as its factorization.

20813393 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 20813393 is about 4562.1697688709. The cubic root of 20813393 is about 275.0727873444.

The spelling of 20813393 in words is "twenty million, eight hundred thirteen thousand, three hundred ninety-three".