19811941 has 2 divisors, whose sum is σ = 19811942. Its totient is φ = 19811940.

The previous prime is 19811923. The next prime is 19811963. The reversal of 19811941 is 14911891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10751841 + 9060100 = 3279^2 + 3010^2 .

It is an emirp because it is prime and its reverse (14911891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19811941 - 2²³ = 11423333 is a prime.

It is a super-3 number, since 3×19811941³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 19811897 and 19811906.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19811921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9905970 + 9905971.

It is an arithmetic number, because the mean of its divisors is an integer number (9905971).

Almost surely, 2^19811941 is an apocalyptic number.

It is an amenable number.

19811941 is a deficient number, since it is larger than the sum of its proper divisors (1).

19811941 is an equidigital number, since it uses as much as digits as its factorization.

19811941 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 34.

The square root of 19811941 is about 4451.0606601124. The cubic root of 19811941 is about 270.5882965760.

The spelling of 19811941 in words is "nineteen million, eight hundred eleven thousand, nine hundred forty-one".