21168587 has 24 divisors (see below), whose sum is σ = 25338096. Its totient is φ = 17600000.

The previous prime is 21168577. The next prime is 21168593. The reversal of 21168587 is 78586112.

It is not a de Polignac number, because 21168587 - 2⁶ = 21168523 is a prime.

It is a Duffinian number.

Its product of digits (26880) is a multiple of the sum of its prime divisors (320).

It is a self number, because there is not a number n which added to its sum of digits gives 21168587.

It is not an unprimeable number, because it can be changed into a prime (21168517) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 84212 + ... + 84462.

It is an arithmetic number, because the mean of its divisors is an integer number (1055754).

Almost surely, 2^21168587 is an apocalyptic number.

21168587 is a deficient number, since it is larger than the sum of its proper divisors (4169509).

21168587 is a wasteful number, since it uses less digits than its factorization.

21168587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331 (or 320 counting only the distinct ones).

The product of its digits is 26880, while the sum is 38.

The square root of 21168587 is about 4600.9332748911. The cubic root of 21168587 is about 276.6287344973.

The spelling of 21168587 in words is "twenty-one million, one hundred sixty-eight thousand, five hundred eighty-seven".