21311489 has 8 divisors (see below), whose sum is σ = 22745088. Its totient is φ = 19897920.

The previous prime is 21311471. The next prime is 21311497. The reversal of 21311489 is 98411312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21311489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21311429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2777 + ... + 7094.

It is an arithmetic number, because the mean of its divisors is an integer number (2843136).

Almost surely, 2^21311489 is an apocalyptic number.

It is an amenable number.

21311489 is a deficient number, since it is larger than the sum of its proper divisors (1433599).

21311489 is a wasteful number, since it uses less digits than its factorization.

21311489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10015.

The product of its digits is 1728, while the sum is 29.

The square root of 21311489 is about 4616.4368294173. The cubic root of 21311489 is about 277.2498148194.

The spelling of 21311489 in words is "twenty-one million, three hundred eleven thousand, four hundred eighty-nine".