21366041 has 2 divisors, whose sum is σ = 21366042. Its totient is φ = 21366040.

The previous prime is 21366017. The next prime is 21366053. The reversal of 21366041 is 14066312.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19175641 + 2190400 = 4379^2 + 1480^2 .

It is a cyclic number.

It is not a de Polignac number, because 21366041 - 2¹⁰ = 21365017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21365998 and 21366016.

It is not a weakly prime, because it can be changed into another prime (21366091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10683020 + 10683021.

It is an arithmetic number, because the mean of its divisors is an integer number (10683021).

Almost surely, 2^21366041 is an apocalyptic number.

It is an amenable number.

21366041 is a deficient number, since it is larger than the sum of its proper divisors (1).

21366041 is an equidigital number, since it uses as much as digits as its factorization.

21366041 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21366041 is about 4622.3415062066. The cubic root of 21366041 is about 277.4861762992.

The spelling of 21366041 in words is "twenty-one million, three hundred sixty-six thousand, forty-one".