21276216 has 64 divisors (see below), whose sum is σ = 63655200. Its totient is φ = 6545664.

The previous prime is 21276209. The next prime is 21276263. The reversal of 21276216 is 61267212.

It is a super-3 number, since 3×21276216³ (a number of 23 digits) contains 333 as substring.

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

It is a zygodrome in base 3.

It is a self number, because there is not a number n which added to its sum of digits gives 21276216.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 981 + ... + 6596.

Almost surely, 2^21276216 is an apocalyptic number.

21276216 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21276216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31827600).

21276216 is an abundant number, since it is smaller than the sum of its proper divisors (42378984).

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

21276216 is a wasteful number, since it uses less digits than its factorization.

21276216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7605 (or 7595 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 21276216 is about 4612.6148766183. The cubic root of 21276216 is about 277.0967700923.

The spelling of 21276216 in words is "twenty-one million, two hundred seventy-six thousand, two hundred sixteen".