21466541 has 2 divisors, whose sum is σ = 21466542. Its totient is φ = 21466540.

The previous prime is 21466519. The next prime is 21466553. The reversal of 21466541 is 14566412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11417641 + 10048900 = 3379^2 + 3170^2 .

It is a cyclic number.

It is not a de Polignac number, because 21466541 - 2¹⁰ = 21465517 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21466141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10733270 + 10733271.

It is an arithmetic number, because the mean of its divisors is an integer number (10733271).

Almost surely, 2^21466541 is an apocalyptic number.

It is an amenable number.

21466541 is a deficient number, since it is larger than the sum of its proper divisors (1).

21466541 is an equidigital number, since it uses as much as digits as its factorization.

21466541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 29.

The square root of 21466541 is about 4633.1998661832. The cubic root of 21466541 is about 277.9205688911.

The spelling of 21466541 in words is "twenty-one million, four hundred sixty-six thousand, five hundred forty-one".