21168487 has 8 divisors (see below), whose sum is σ = 22265856. Its totient is φ = 20085912.

The previous prime is 21168481. The next prime is 21168491. The reversal of 21168487 is 78486112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21168487 - 2³ = 21168479 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 (21168481) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 703 + ... + 6544.

It is an arithmetic number, because the mean of its divisors is an integer number (2783232).

Almost surely, 2^21168487 is an apocalyptic number.

21168487 is a deficient number, since it is larger than the sum of its proper divisors (1097369).

21168487 is a wasteful number, since it uses less digits than its factorization.

21168487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7397.

The product of its digits is 21504, while the sum is 37.

The square root of 21168487 is about 4600.9224075179. The cubic root of 21168487 is about 276.6282989004.

The spelling of 21168487 in words is "twenty-one million, one hundred sixty-eight thousand, four hundred eighty-seven".