21871696 has 80 divisors (see below), whose sum is σ = 54246528. Its totient is φ = 8294400.

The previous prime is 21871667. The next prime is 21871721. The reversal of 21871696 is 69617812.

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, 50296 + ... + 50728.

Almost surely, 2^21871696 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 21871696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27123264).

21871696 is an abundant number, since it is smaller than the sum of its proper divisors (32374832).

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

21871696 is a wasteful number, since it uses less digits than its factorization.

21871696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500 (or 494 counting only the distinct ones).

The product of its digits is 36288, while the sum is 40.

The square root of 21871696 is about 4676.7185076718. The cubic root of 21871696 is about 279.6581542466.

It can be divided in two parts, 218716 and 96, that added together give a palindrome (218812).

The spelling of 21871696 in words is "twenty-one million, eight hundred seventy-one thousand, six hundred ninety-six".