21727116 has 42 divisors (see below), whose sum is σ = 57015252. Its totient is φ = 7241400.

The previous prime is 21727109. The next prime is 21727117. The reversal of 21727116 is 61172712.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 21727116.

It is not an unprimeable number, because it can be changed into a prime (21727117) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 810 + ... + 6641.

It is an arithmetic number, because the mean of its divisors is an integer number (1357506).

Almost surely, 2^21727116 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21727116, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28507626).

21727116 is an abundant number, since it is smaller than the sum of its proper divisors (35288136).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21727116 is an equidigital number, since it uses as much as digits as its factorization.

21727116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7473 (or 7456 counting only the distinct ones).

The product of its digits is 1176, while the sum is 27.

The square root of 21727116 is about 4661.2354585453. The cubic root of 21727116 is about 279.0405768247.

Adding to 21727116 its reverse (61172712), we get a palindrome (82899828).

The spelling of 21727116 in words is "twenty-one million, seven hundred twenty-seven thousand, one hundred sixteen".