21693936 has 80 divisors (see below), whose sum is σ = 61746048. Its totient is φ = 6508800.

The previous prime is 21693911. The next prime is 21693937. The reversal of 21693936 is 63939612.

It is a junction number, because it is equal to n+sod(n) for n = 21693894 and 21693903.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21693937) 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 15 ways as a sum of consecutive naturals, for example, 95455 + ... + 95681.

Almost surely, 2^21693936 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 21693936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30873024).

21693936 is an abundant number, since it is smaller than the sum of its proper divisors (40052112).

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

21693936 is a wasteful number, since it uses less digits than its factorization.

21693936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430 (or 424 counting only the distinct ones).

The product of its digits is 52488, while the sum is 39.

The square root of 21693936 is about 4657.6749564563. The cubic root of 21693936 is about 278.8984612714.

It can be divided in two parts, 2169 and 3936, that added together give a triangular number (6105 = T₁₁₀).

The spelling of 21693936 in words is "twenty-one million, six hundred ninety-three thousand, nine hundred thirty-six".