21041539 has 2 divisors, whose sum is σ = 21041540. Its totient is φ = 21041538.

The previous prime is 21041533. The next prime is 21041543. The reversal of 21041539 is 93514012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21041539 - 2⁷ = 21041411 is a prime.

It is not a weakly prime, because it can be changed into another prime (21041533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10520769 + 10520770.

It is an arithmetic number, because the mean of its divisors is an integer number (10520770).

Almost surely, 2^21041539 is an apocalyptic number.

21041539 is a deficient number, since it is larger than the sum of its proper divisors (1).

21041539 is an equidigital number, since it uses as much as digits as its factorization.

21041539 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 21041539 is about 4587.1057323764. The cubic root of 21041539 is about 276.0742072745.

The spelling of 21041539 in words is "twenty-one million, forty-one thousand, five hundred thirty-nine".