18691441 has 2 divisors, whose sum is σ = 18691442. Its totient is φ = 18691440.

The previous prime is 18691427. The next prime is 18691487. The reversal of 18691441 is 14419681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10112400 + 8579041 = 3180^2 + 2929^2 .

It is a cyclic number.

It is not a de Polignac number, because 18691441 - 2⁹ = 18690929 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18691397 and 18691406.

It is not a weakly prime, because it can be changed into another prime (18691241) 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, 9345720 + 9345721.

It is an arithmetic number, because the mean of its divisors is an integer number (9345721).

Almost surely, 2^18691441 is an apocalyptic number.

It is an amenable number.

18691441 is a deficient number, since it is larger than the sum of its proper divisors (1).

18691441 is an equidigital number, since it uses as much as digits as its factorization.

18691441 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6912, while the sum is 34.

The square root of 18691441 is about 4323.3599202472. The cubic root of 18691441 is about 265.3877839916.

The spelling of 18691441 in words is "eighteen million, six hundred ninety-one thousand, four hundred forty-one".