21428352 has 192 divisors, whose sum is σ = 71604000. Its totient is φ = 6082560.

The previous prime is 21428339. The next prime is 21428383. The reversal of 21428352 is 25382412.

It is a tau number, because it is divible by the number of its divisors (192).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 240724 + ... + 240812.

Almost surely, 2^21428352 is an apocalyptic number.

21428352 is a gapful number since it is divisible by the number (22) 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 21428352, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35802000).

21428352 is an abundant number, since it is smaller than the sum of its proper divisors (50175648).

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

21428352 is a wasteful number, since it uses less digits than its factorization.

21428352 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 124 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

The square root of 21428352 is about 4629.0767978075. The cubic root of 21428352 is about 277.7556640648.

The spelling of 21428352 in words is "twenty-one million, four hundred twenty-eight thousand, three hundred fifty-two".