21270912 has 64 divisors (see below), whose sum is σ = 60861360. Its totient is φ = 6543360.

The previous prime is 21270881. The next prime is 21270919. The reversal of 21270912 is 21907212.

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

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21270919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2862 + ... + 7122.

Almost surely, 2^21270912 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 21270912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30430680).

21270912 is an abundant number, since it is smaller than the sum of its proper divisors (39590448).

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

21270912 is a wasteful number, since it uses less digits than its factorization.

21270912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4291 (or 4279 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 21270912 is about 4612.0398957511. The cubic root of 21270912 is about 277.0737421344.

The spelling of 21270912 in words is "twenty-one million, two hundred seventy thousand, nine hundred twelve".