21046841 has 2 divisors, whose sum is σ = 21046842. Its totient is φ = 21046840.

The previous prime is 21046819. The next prime is 21046847. The reversal of 21046841 is 14864012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19536400 + 1510441 = 4420^2 + 1229^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21046841 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21046841.

It is not a weakly prime, because it can be changed into another prime (21046847) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10523420 + 10523421.

It is an arithmetic number, because the mean of its divisors is an integer number (10523421).

Almost surely, 2^21046841 is an apocalyptic number.

It is an amenable number.

21046841 is a deficient number, since it is larger than the sum of its proper divisors (1).

21046841 is an equidigital number, since it uses as much as digits as its factorization.

21046841 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 21046841 is about 4587.6836203034. The cubic root of 21046841 is about 276.0973935145.

The spelling of 21046841 in words is "twenty-one million, forty-six thousand, eight hundred forty-one".