20426389 has 2 divisors, whose sum is σ = 20426390. Its totient is φ = 20426388.

The previous prime is 20426321. The next prime is 20426423. The reversal of 20426389 is 98362402.

It is an a-pointer prime, because the next prime (20426423) can be obtained adding 20426389 to its sum of digits (34).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17363889 + 3062500 = 4167^2 + 1750^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20426389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20426309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10213194 + 10213195.

It is an arithmetic number, because the mean of its divisors is an integer number (10213195).

Almost surely, 2^20426389 is an apocalyptic number.

It is an amenable number.

20426389 is a deficient number, since it is larger than the sum of its proper divisors (1).

20426389 is an equidigital number, since it uses as much as digits as its factorization.

20426389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 20426389 is about 4519.5562835305. The cubic root of 20426389 is about 273.3572097260.

It can be divided in two parts, 20 and 426389, that added together give a square (426409 = 653²).

The spelling of 20426389 in words is "twenty million, four hundred twenty-six thousand, three hundred eighty-nine".