21300591 has 12 divisors (see below), whose sum is σ = 30754248. Its totient is φ = 13107744.

The previous prime is 21300583. The next prime is 21300619. The reversal of 21300591 is 19500312.

It is not a de Polignac number, because 21300591 - 2³ = 21300583 is a prime.

It is a Smith number, since the sum of its digits (21) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21300551) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20500 + ... + 21513.

It is an arithmetic number, because the mean of its divisors is an integer number (2562854).

Almost surely, 2^21300591 is an apocalyptic number.

21300591 is a deficient number, since it is larger than the sum of its proper divisors (9453657).

21300591 is a wasteful number, since it uses less digits than its factorization.

21300591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42042 (or 42029 counting only the distinct ones).

The product of its (nonzero) digits is 270, while the sum is 21.

The square root of 21300591 is about 4615.2563309095. The cubic root of 21300591 is about 277.2025479257.

The spelling of 21300591 in words is "twenty-one million, three hundred thousand, five hundred ninety-one".