21194441 has 2 divisors, whose sum is σ = 21194442. Its totient is φ = 21194440.

The previous prime is 21194387. The next prime is 21194479. The reversal of 21194441 is 14449112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20839225 + 355216 = 4565^2 + 596^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21194441 is a prime.

It is a Sophie Germain prime.

It is a Chen 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 21194441.

It is not a weakly prime, because it can be changed into another prime (21190441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10597220 + 10597221.

It is an arithmetic number, because the mean of its divisors is an integer number (10597221).

Almost surely, 2^21194441 is an apocalyptic number.

It is an amenable number.

21194441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21194441 is an equidigital number, since it uses as much as digits as its factorization.

21194441 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 26.

The square root of 21194441 is about 4603.7420648859. The cubic root of 21194441 is about 276.7413077428.

The spelling of 21194441 in words is "twenty-one million, one hundred ninety-four thousand, four hundred forty-one".