21206593 has 2 divisors, whose sum is σ = 21206594. Its totient is φ = 21206592.

The previous prime is 21206579. The next prime is 21206609. The reversal of 21206593 is 39560212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15745024 + 5461569 = 3968^2 + 2337^2 .

It is a cyclic number.

It is not a de Polignac number, because 21206593 - 2⁵ = 21206561 is a prime.

It is not a weakly prime, because it can be changed into another prime (21206533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10603296 + 10603297.

It is an arithmetic number, because the mean of its divisors is an integer number (10603297).

Almost surely, 2^21206593 is an apocalyptic number.

It is an amenable number.

21206593 is a deficient number, since it is larger than the sum of its proper divisors (1).

21206593 is an equidigital number, since it uses as much as digits as its factorization.

21206593 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 21206593 is about 4605.0616716826. The cubic root of 21206593 is about 276.7941882418.

The spelling of 21206593 in words is "twenty-one million, two hundred six thousand, five hundred ninety-three".