21229936 has 60 divisors (see below), whose sum is σ = 51553992. Its totient is φ = 8394624.

The previous prime is 21229927. The next prime is 21229951. The reversal of 21229936 is 63992212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9151 + ... + 11233.

Almost surely, 2^21229936 is an apocalyptic number.

21229936 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21229936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25776996).

21229936 is an abundant number, since it is smaller than the sum of its proper divisors (30324056).

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

21229936 is a wasteful number, since it uses less digits than its factorization.

21229936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2118 (or 2105 counting only the distinct ones).

The product of its digits is 11664, while the sum is 34.

The square root of 21229936 is about 4607.5954683544. The cubic root of 21229936 is about 276.8957107177.

The spelling of 21229936 in words is "twenty-one million, two hundred twenty-nine thousand, nine hundred thirty-six".