21574887 has 16 divisors (see below), whose sum is σ = 30707712. Its totient is φ = 13426560.

The previous prime is 21574879. The next prime is 21574901. The reversal of 21574887 is 78847512.

It is not a de Polignac number, because 21574887 - 2³ = 21574879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21574867) 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 15 ways as a sum of consecutive naturals, for example, 4812 + ... + 8142.

It is an arithmetic number, because the mean of its divisors is an integer number (1919232).

Almost surely, 2^21574887 is an apocalyptic number.

21574887 is a deficient number, since it is larger than the sum of its proper divisors (9132825).

21574887 is a wasteful number, since it uses less digits than its factorization.

21574887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3478.

The product of its digits is 125440, while the sum is 42.

The square root of 21574887 is about 4644.8775010758. The cubic root of 21574887 is about 278.3873583282.

The spelling of 21574887 in words is "twenty-one million, five hundred seventy-four thousand, eight hundred eighty-seven".