21059837 has 2 divisors, whose sum is σ = 21059838. Its totient is φ = 21059836.

The previous prime is 21059833. The next prime is 21059849. The reversal of 21059837 is 73895012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20557156 + 502681 = 4534^2 + 709^2 .

It is a cyclic number.

It is not a de Polignac number, because 21059837 - 2² = 21059833 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21059797 and 21059806.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21059833) 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, 10529918 + 10529919.

It is an arithmetic number, because the mean of its divisors is an integer number (10529919).

Almost surely, 2^21059837 is an apocalyptic number.

It is an amenable number.

21059837 is a deficient number, since it is larger than the sum of its proper divisors (1).

21059837 is an equidigital number, since it uses as much as digits as its factorization.

21059837 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 21059837 is about 4589.0998027936. The cubic root of 21059837 is about 276.1542100132.

The spelling of 21059837 in words is "twenty-one million, fifty-nine thousand, eight hundred thirty-seven".