21110587 has 4 divisors (see below), whose sum is σ = 21119920. Its totient is φ = 21101256.

The previous prime is 21110543. The next prime is 21110591. The reversal of 21110587 is 78501112.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21110587 - 2¹¹ = 21108539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21116587) 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 in 3 ways as a sum of consecutive naturals, for example, 1114 + ... + 6592.

It is an arithmetic number, because the mean of its divisors is an integer number (5279980).

Almost surely, 2^21110587 is an apocalyptic number.

21110587 is a deficient number, since it is larger than the sum of its proper divisors (9333).

21110587 is an equidigital number, since it uses as much as digits as its factorization.

21110587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9332.

The product of its (nonzero) digits is 560, while the sum is 25.

The square root of 21110587 is about 4594.6258824849. The cubic root of 21110587 is about 276.3758575590.

Adding to 21110587 its reverse (78501112), we get a palindrome (99611699).

The spelling of 21110587 in words is "twenty-one million, one hundred ten thousand, five hundred eighty-seven".