21920896 has 32 divisors (see below), whose sum is σ = 44746380. Its totient is φ = 10690560.

The previous prime is 21920891. The next prime is 21920903. The reversal of 21920896 is 69802912.

It can be written as a sum of positive squares in 2 ways, for example, as 21902400 + 18496 = 4680^2 + 136^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (21920891) 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 3 ways as a sum of consecutive naturals, for example, 3160 + ... + 7336.

Almost surely, 2^21920896 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 21920896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22373190).

21920896 is an abundant number, since it is smaller than the sum of its proper divisors (22825484).

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

21920896 is an equidigital number, since it uses as much as digits as its factorization.

21920896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4232 (or 4220 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 21920896 is about 4681.9756513677. The cubic root of 21920896 is about 279.8676925931.

It can be divided in two parts, 219 and 20896, that added together give a triangular number (21115 = T₂₀₅).

The spelling of 21920896 in words is "twenty-one million, nine hundred twenty thousand, eight hundred ninety-six".