21191296 has 64 divisors (see below), whose sum is σ = 49106880. Its totient is φ = 8921088.

The previous prime is 21191279. The next prime is 21191309. The reversal of 21191296 is 69219112.

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

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59856 + ... + 60208.

It is an arithmetic number, because the mean of its divisors is an integer number (767295).

Almost surely, 2^21191296 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 21191296, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24553440).

21191296 is an abundant number, since it is smaller than the sum of its proper divisors (27915584).

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

21191296 is an equidigital number, since it uses as much as digits as its factorization.

21191296 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441 (or 429 counting only the distinct ones).

The product of its digits is 1944, while the sum is 31.

The square root of 21191296 is about 4603.4004822522. The cubic root of 21191296 is about 276.7276187057.

The spelling of 21191296 in words is "twenty-one million, one hundred ninety-one thousand, two hundred ninety-six".