21332165 has 8 divisors (see below), whose sum is σ = 26290680. Its totient is φ = 16604352.

The previous prime is 21332159. The next prime is 21332183. The reversal of 21332165 is 56123312.

It can be written as a sum of positive squares in 4 ways, for example, as 2244004 + 19088161 = 1498^2 + 4369^2 .

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 21332165 - 2¹⁶ = 21266629 is a prime.

It is a super-2 number, since 2×21332165² = 910122527174450, 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 21332165.

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, 57470 + ... + 57839.

It is an arithmetic number, because the mean of its divisors is an integer number (3286335).

Almost surely, 2^21332165 is an apocalyptic number.

It is an amenable number.

21332165 is a deficient number, since it is larger than the sum of its proper divisors (4958515).

21332165 is a wasteful number, since it uses less digits than its factorization.

21332165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115351.

The product of its digits is 1080, while the sum is 23.

The square root of 21332165 is about 4618.6756759920. The cubic root of 21332165 is about 277.3394466660.

Adding to 21332165 its reverse (56123312), we get a palindrome (77455477).

The spelling of 21332165 in words is "twenty-one million, three hundred thirty-two thousand, one hundred sixty-five".