21993876 has 48 divisors (see below), whose sum is σ = 58423680. Its totient is φ = 7151040.

The previous prime is 21993871. The next prime is 21993893. The reversal of 21993876 is 67839912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21993871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1945 + ... + 6911.

It is an arithmetic number, because the mean of its divisors is an integer number (1217160).

Almost surely, 2^21993876 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 21993876, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29211840).

21993876 is an abundant number, since it is smaller than the sum of its proper divisors (36429804).

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

21993876 is a wasteful number, since it uses less digits than its factorization.

21993876 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5021 (or 5013 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 21993876 is about 4689.7628937932. The cubic root of 21993876 is about 280.1779311241.

The spelling of 21993876 in words is "twenty-one million, nine hundred ninety-three thousand, eight hundred seventy-six".