21759041 has 2 divisors, whose sum is σ = 21759042. Its totient is φ = 21759040.

The previous prime is 21759029. The next prime is 21759043. The reversal of 21759041 is 14095712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21529600 + 229441 = 4640^2 + 479^2 .

It is a cyclic number.

It is not a de Polignac number, because 21759041 - 2⁶ = 21758977 is a prime.

Together with 21759043, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21758995 and 21759013.

It is not a weakly prime, because it can be changed into another prime (21759043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10879520 + 10879521.

It is an arithmetic number, because the mean of its divisors is an integer number (10879521).

Almost surely, 2^21759041 is an apocalyptic number.

It is an amenable number.

21759041 is a deficient number, since it is larger than the sum of its proper divisors (1).

21759041 is an equidigital number, since it uses as much as digits as its factorization.

21759041 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 29.

The square root of 21759041 is about 4664.6587227792. The cubic root of 21759041 is about 279.1771804857.

The spelling of 21759041 in words is "twenty-one million, seven hundred fifty-nine thousand, forty-one".