21308059 has 2 divisors, whose sum is σ = 21308060. Its totient is φ = 21308058.

The previous prime is 21308057. The next prime is 21308081. The reversal of 21308059 is 95080312.

21308059 = 1882² + 1883² + ... + 1887².

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21308059 - 2¹ = 21308057 is a prime.

Together with 21308057, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21308057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10654029 + 10654030.

It is an arithmetic number, because the mean of its divisors is an integer number (10654030).

Almost surely, 2^21308059 is an apocalyptic number.

21308059 is a deficient number, since it is larger than the sum of its proper divisors (1).

21308059 is an equidigital number, since it uses as much as digits as its factorization.

21308059 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 21308059 is about 4616.0653158291. The cubic root of 21308059 is about 277.2349399337.

The spelling of 21308059 in words is "twenty-one million, three hundred eight thousand, fifty-nine".