20038981 has 2 divisors, whose sum is σ = 20038982. Its totient is φ = 20038980.

The previous prime is 20038979. The next prime is 20038987. The reversal of 20038981 is 18983002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19980900 + 58081 = 4470^2 + 241^2 .

It is a cyclic number.

It is not a de Polignac number, because 20038981 - 2¹ = 20038979 is a prime.

It is a super-2 number, since 2×20038981² = 803121519036722, which contains 22 as substring.

Together with 20038979, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20038987) 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, 10019490 + 10019491.

It is an arithmetic number, because the mean of its divisors is an integer number (10019491).

Almost surely, 2^20038981 is an apocalyptic number.

It is an amenable number.

20038981 is a deficient number, since it is larger than the sum of its proper divisors (1).

20038981 is an equidigital number, since it uses as much as digits as its factorization.

20038981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 20038981 is about 4476.4920417666. The cubic root of 20038981 is about 271.6179983995.

The spelling of 20038981 in words is "twenty million, thirty-eight thousand, nine hundred eighty-one".