21248087 has 4 divisors (see below), whose sum is σ = 24283536. Its totient is φ = 18212640.

The previous prime is 21248081. The next prime is 21248093. The reversal of 21248087 is 78084212.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21248081) and next prime (21248093).

It is a cyclic number.

It is not a de Polignac number, because 21248087 - 2¹⁰ = 21247063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21248081) 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 in 3 ways as a sum of consecutive naturals, for example, 1517714 + ... + 1517727.

It is an arithmetic number, because the mean of its divisors is an integer number (6070884).

Almost surely, 2^21248087 is an apocalyptic number.

21248087 is a deficient number, since it is larger than the sum of its proper divisors (3035449).

21248087 is an equidigital number, since it uses as much as digits as its factorization.

21248087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3035448.

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 21248087 is about 4609.5647299935. The cubic root of 21248087 is about 276.9746009285.

The spelling of 21248087 in words is "twenty-one million, two hundred forty-eight thousand, eighty-seven".