21996072 has 96 divisors (see below), whose sum is σ = 71697600. Its totient is φ = 5951232.

The previous prime is 21996041. The next prime is 21996077. The reversal of 21996072 is 27069912.

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

It is not an unprimeable number, because it can be changed into a prime (21996077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8428 + ... + 10724.

It is an arithmetic number, because the mean of its divisors is an integer number (746850).

Almost surely, 2^21996072 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 21996072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35848800).

21996072 is an abundant number, since it is smaller than the sum of its proper divisors (49701528).

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

21996072 is a wasteful number, since it uses less digits than its factorization.

21996072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2335 (or 2328 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 21996072 is about 4689.9970149244. The cubic root of 21996072 is about 280.1872556934.

The spelling of 21996072 in words is "twenty-one million, nine hundred ninety-six thousand, seventy-two".