21871296 has 70 divisors (see below), whose sum is σ = 64848740. Its totient is φ = 7288704.

The previous prime is 21871273. The next prime is 21871303. The reversal of 21871296 is 69217812.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21871296.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 3075 + ... + 7293.

Almost surely, 2^21871296 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 21871296, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32424370).

21871296 is an abundant number, since it is smaller than the sum of its proper divisors (42977444).

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

21871296 is an equidigital number, since it uses as much as digits as its factorization.

21871296 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4243 (or 4224 counting only the distinct ones).

The product of its digits is 12096, while the sum is 36.

The square root of 21871296 is about 4676.6757424478. The cubic root of 21871296 is about 279.6564493956.

The spelling of 21871296 in words is "twenty-one million, eight hundred seventy-one thousand, two hundred ninety-six".