21574428 has 36 divisors (see below), whose sum is σ = 53484312. Its totient is φ = 6767360.

The previous prime is 21574417. The next prime is 21574429. The reversal of 21574428 is 82447512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21574429) 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 11 ways as a sum of consecutive naturals, for example, 358 + ... + 6578.

Almost surely, 2^21574428 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 21574428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26742156).

21574428 is an abundant number, since it is smaller than the sum of its proper divisors (31909884).

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

21574428 is a wasteful number, since it uses less digits than its factorization.

21574428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6262 (or 6243 counting only the distinct ones).

The product of its digits is 17920, while the sum is 33.

The square root of 21574428 is about 4644.8280915444. The cubic root of 21574428 is about 278.3853841085.

The spelling of 21574428 in words is "twenty-one million, five hundred seventy-four thousand, four hundred twenty-eight".