21587133 has 8 divisors (see below), whose sum is σ = 30034368. Its totient is φ = 13765664.

The previous prime is 21587131. The next prime is 21587149. The reversal of 21587133 is 33178512.

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 21587133 - 2¹ = 21587131 is a prime.

It is a super-2 number, since 2×21587133² = 932008622319378, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21587133.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21587131) 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 7 ways as a sum of consecutive naturals, for example, 156360 + ... + 156497.

It is an arithmetic number, because the mean of its divisors is an integer number (3754296).

Almost surely, 2^21587133 is an apocalyptic number.

21587133 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21587133 is a deficient number, since it is larger than the sum of its proper divisors (8447235).

21587133 is a wasteful number, since it uses less digits than its factorization.

21587133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312883.

The product of its digits is 5040, while the sum is 30.

The square root of 21587133 is about 4646.1955404395. The cubic root of 21587133 is about 278.4400196590.

The spelling of 21587133 in words is "twenty-one million, five hundred eighty-seven thousand, one hundred thirty-three".