20444381 has 2 divisors, whose sum is σ = 20444382. Its totient is φ = 20444380.

The previous prime is 20444371. The next prime is 20444429. The reversal of 20444381 is 18344402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18567481 + 1876900 = 4309^2 + 1370^2 .

It is a cyclic number.

It is not a de Polignac number, because 20444381 - 2¹⁴ = 20427997 is a prime.

It is a super-2 number, since 2×20444381² = 835945428946322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20444381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20444341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10222190 + 10222191.

It is an arithmetic number, because the mean of its divisors is an integer number (10222191).

Almost surely, 2^20444381 is an apocalyptic number.

It is an amenable number.

20444381 is a deficient number, since it is larger than the sum of its proper divisors (1).

20444381 is an equidigital number, since it uses as much as digits as its factorization.

20444381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3072, while the sum is 26.

The square root of 20444381 is about 4521.5463062983. The cubic root of 20444381 is about 273.4374457970.

Adding to 20444381 its reverse (18344402), we get a palindrome (38788783).

The spelling of 20444381 in words is "twenty million, four hundred forty-four thousand, three hundred eighty-one".