21416165 has 8 divisors (see below), whose sum is σ = 25766520. Its totient is φ = 17088192.

The previous prime is 21416117. The next prime is 21416167. The reversal of 21416165 is 56161412.

It can be written as a sum of positive squares in 4 ways, for example, as 3020644 + 18395521 = 1738^2 + 4289^2 .

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 21416165 - 2¹⁶ = 21350629 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21416167) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3410 + ... + 7379.

It is an arithmetic number, because the mean of its divisors is an integer number (3220815).

Almost surely, 2^21416165 is an apocalyptic number.

It is an amenable number.

21416165 is a deficient number, since it is larger than the sum of its proper divisors (4350355).

21416165 is a wasteful number, since it uses less digits than its factorization.

21416165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11191.

The product of its digits is 1440, while the sum is 26.

The square root of 21416165 is about 4627.7602574031. The cubic root of 21416165 is about 277.7029978557.

Adding to 21416165 its reverse (56161412), we get a palindrome (77577577).

The spelling of 21416165 in words is "twenty-one million, four hundred sixteen thousand, one hundred sixty-five".