20789393 has 2 divisors, whose sum is σ = 20789394. Its totient is φ = 20789392.

The previous prime is 20789371. The next prime is 20789399. The reversal of 20789393 is 39398702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20638849 + 150544 = 4543^2 + 388^2 .

It is a cyclic number.

It is not a de Polignac number, because 20789393 - 2¹⁸ = 20527249 is a prime.

It is a super-2 number, since 2×20789393² = 864397722616898, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20789393.

It is not a weakly prime, because it can be changed into another prime (20789399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10394696 + 10394697.

It is an arithmetic number, because the mean of its divisors is an integer number (10394697).

Almost surely, 2^20789393 is an apocalyptic number.

It is an amenable number.

20789393 is a deficient number, since it is larger than the sum of its proper divisors (1).

20789393 is an equidigital number, since it uses as much as digits as its factorization.

20789393 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81648, while the sum is 41.

The square root of 20789393 is about 4559.5386828055. The cubic root of 20789393 is about 274.9670175320.

The spelling of 20789393 in words is "twenty million, seven hundred eighty-nine thousand, three hundred ninety-three".