21194688 has 56 divisors (see below), whose sum is σ = 57058560. Its totient is φ = 6941440.

The previous prime is 21194683. The next prime is 21194689. The reversal of 21194688 is 88649112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21194683) 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, 10393 + ... + 12263.

Almost surely, 2^21194688 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 21194688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28529280).

21194688 is an abundant number, since it is smaller than the sum of its proper divisors (35863872).

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

21194688 is a wasteful number, since it uses less digits than its factorization.

21194688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1945 (or 1935 counting only the distinct ones).

The product of its digits is 27648, while the sum is 39.

The square root of 21194688 is about 4603.7688908111. The cubic root of 21194688 is about 276.7423827863.

The spelling of 21194688 in words is "twenty-one million, one hundred ninety-four thousand, six hundred eighty-eight".