21437441 has 2 divisors, whose sum is σ = 21437442. Its totient is φ = 21437440.

The previous prime is 21437431. The next prime is 21437443. The reversal of 21437441 is 14473412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20976400 + 461041 = 4580^2 + 679^2 .

It is a cyclic number.

It is not a de Polignac number, because 21437441 - 2¹⁰ = 21436417 is a prime.

Together with 21437443, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21437441.

It is not a weakly prime, because it can be changed into another prime (21437443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10718720 + 10718721.

It is an arithmetic number, because the mean of its divisors is an integer number (10718721).

Almost surely, 2^21437441 is an apocalyptic number.

It is an amenable number.

21437441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21437441 is an equidigital number, since it uses as much as digits as its factorization.

21437441 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2688, while the sum is 26.

The square root of 21437441 is about 4630.0584229575. The cubic root of 21437441 is about 277.7949292461.

The spelling of 21437441 in words is "twenty-one million, four hundred thirty-seven thousand, four hundred forty-one".