20239381 has 2 divisors, whose sum is σ = 20239382. Its totient is φ = 20239380.

The previous prime is 20239337. The next prime is 20239399. The reversal of 20239381 is 18393202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12895281 + 7344100 = 3591^2 + 2710^2 .

It is a cyclic number.

It is not a de Polignac number, because 20239381 - 2⁷ = 20239253 is a prime.

It is a super-2 number, since 2×20239381² = 819265086526322, which contains 22 as substring.

It is a Chen prime.

It is equal to p_1284823 and since 20239381 and 1284823 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20239321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10119690 + 10119691.

It is an arithmetic number, because the mean of its divisors is an integer number (10119691).

Almost surely, 2^20239381 is an apocalyptic number.

It is an amenable number.

20239381 is a deficient number, since it is larger than the sum of its proper divisors (1).

20239381 is an equidigital number, since it uses as much as digits as its factorization.

20239381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 20239381 is about 4498.8199563886. The cubic root of 20239381 is about 272.5204361409.

The spelling of 20239381 in words is "twenty million, two hundred thirty-nine thousand, three hundred eighty-one".