21976448 has 64 divisors (see below), whose sum is σ = 48323520. Its totient is φ = 9891840.

The previous prime is 21976441. The next prime is 21976463. The reversal of 21976448 is 84467912.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21976441) 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 7 ways as a sum of consecutive naturals, for example, 78068 + ... + 78348.

It is an arithmetic number, because the mean of its divisors is an integer number (755055).

Almost surely, 2^21976448 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 21976448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24161760).

21976448 is an abundant number, since it is smaller than the sum of its proper divisors (26347072).

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

21976448 is a wasteful number, since it uses less digits than its factorization.

21976448 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355 (or 343 counting only the distinct ones).

The product of its digits is 96768, while the sum is 41.

The square root of 21976448 is about 4687.9044358860. The cubic root of 21976448 is about 280.1039070139.

It can be divided in two parts, 219 and 76448, that added together give a palindrome (76667).

The spelling of 21976448 in words is "twenty-one million, nine hundred seventy-six thousand, four hundred forty-eight".