20839381 has 2 divisors, whose sum is σ = 20839382. Its totient is φ = 20839380.

The previous prime is 20839373. The next prime is 20839393. The reversal of 20839381 is 18393802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18198756 + 2640625 = 4266^2 + 1625^2 .

It is a cyclic number.

It is not a de Polignac number, because 20839381 - 2³ = 20839373 is a prime.

It is a super-2 number, since 2×20839381² = 868559600926322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20837381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10419690 + 10419691.

It is an arithmetic number, because the mean of its divisors is an integer number (10419691).

Almost surely, 2^20839381 is an apocalyptic number.

It is an amenable number.

20839381 is a deficient number, since it is larger than the sum of its proper divisors (1).

20839381 is an equidigital number, since it uses as much as digits as its factorization.

20839381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 20839381 is about 4565.0170864960. The cubic root of 20839381 is about 275.1872267724.

The spelling of 20839381 in words is "twenty million, eight hundred thirty-nine thousand, three hundred eighty-one".