21327887 has 6 divisors (see below), whose sum is σ = 24810048. Its totient is φ = 18281004.

The previous prime is 21327883. The next prime is 21327893. The reversal of 21327887 is 78872312.

It is not a de Polignac number, because 21327887 - 2² = 21327883 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21327887.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21327883) 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 5 ways as a sum of consecutive naturals, for example, 217583 + ... + 217680.

It is an arithmetic number, because the mean of its divisors is an integer number (4135008).

Almost surely, 2^21327887 is an apocalyptic number.

21327887 is a deficient number, since it is larger than the sum of its proper divisors (3482161).

21327887 is an equidigital number, since it uses as much as digits as its factorization.

21327887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435277 (or 435270 counting only the distinct ones).

The product of its digits is 37632, while the sum is 38.

The square root of 21327887 is about 4618.2125330045. The cubic root of 21327887 is about 277.3209060026.

The spelling of 21327887 in words is "twenty-one million, three hundred twenty-seven thousand, eight hundred eighty-seven".