21819936 has 48 divisors (see below), whose sum is σ = 58834944. Its totient is φ = 7075584.

The previous prime is 21819929. The next prime is 21819943. The reversal of 21819936 is 63991812.

It is an interprime number because it is at equal distance from previous prime (21819929) and next prime (21819943).

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×21819936² = 952219214088192, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21819894 and 21819903.

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, 481 + ... + 6623.

It is an arithmetic number, because the mean of its divisors is an integer number (1225728).

Almost surely, 2^21819936 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 21819936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29417472).

21819936 is an abundant number, since it is smaller than the sum of its proper divisors (37015008).

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

21819936 is a wasteful number, since it uses less digits than its factorization.

21819936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6193 (or 6185 counting only the distinct ones).

The product of its digits is 23328, while the sum is 39.

The square root of 21819936 is about 4671.1814351404. The cubic root of 21819936 is about 279.4373736285.

The spelling of 21819936 in words is "twenty-one million, eight hundred nineteen thousand, nine hundred thirty-six".