21231165 has 8 divisors (see below), whose sum is σ = 33969888. Its totient is φ = 11323280.

The previous prime is 21231143. The next prime is 21231173. The reversal of 21231165 is 56113212.

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

It is not a de Polignac number, because 21231165 - 2¹⁰ = 21230141 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 707691 + ... + 707720.

It is an arithmetic number, because the mean of its divisors is an integer number (4246236).

Almost surely, 2^21231165 is an apocalyptic number.

It is an amenable number.

21231165 is a deficient number, since it is larger than the sum of its proper divisors (12738723).

21231165 is a wasteful number, since it uses less digits than its factorization.

21231165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1415419.

The product of its digits is 360, while the sum is 21.

The square root of 21231165 is about 4607.7288331672. The cubic root of 21231165 is about 276.9010537745.

Adding to 21231165 its reverse (56113212), we get a palindrome (77344377).

The spelling of 21231165 in words is "twenty-one million, two hundred thirty-one thousand, one hundred sixty-five".