21040559 has 2 divisors, whose sum is σ = 21040560. Its totient is φ = 21040558.

The previous prime is 21040549. The next prime is 21040601. The reversal of 21040559 is 95504012.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21040559 is a prime.

It is equal to p_1332386 and since 21040559 and 1332386 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21040519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10520279 + 10520280.

It is an arithmetic number, because the mean of its divisors is an integer number (10520280).

Almost surely, 2^21040559 is an apocalyptic number.

21040559 is a deficient number, since it is larger than the sum of its proper divisors (1).

21040559 is an equidigital number, since it uses as much as digits as its factorization.

21040559 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 21040559 is about 4586.9989099628. The cubic root of 21040559 is about 276.0699211982.

The spelling of 21040559 in words is "twenty-one million, forty thousand, five hundred fifty-nine".