21540059 has 2 divisors, whose sum is σ = 21540060. Its totient is φ = 21540058.

The previous prime is 21540049. The next prime is 21540083. The reversal of 21540059 is 95004512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21540059 - 2¹² = 21535963 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21540019) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10770029 + 10770030.

It is an arithmetic number, because the mean of its divisors is an integer number (10770030).

Almost surely, 2^21540059 is an apocalyptic number.

21540059 is a deficient number, since it is larger than the sum of its proper divisors (1).

21540059 is an equidigital number, since it uses as much as digits as its factorization.

21540059 is an odious number, because the sum of its binary digits is odd.

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

The square root of 21540059 is about 4641.1269105682. The cubic root of 21540059 is about 278.2374788752.

The spelling of 21540059 in words is "twenty-one million, five hundred forty thousand, fifty-nine".