21353652 has 48 divisors (see below), whose sum is σ = 55746880. Its totient is φ = 7068384.

The previous prime is 21353639. The next prime is 21353711. The reversal of 21353652 is 25635312.

21353652 is a `hidden beast` number, since 2 + 1 + 3 + 5 + 3 + 652 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16998 + ... + 18210.

Almost surely, 2^21353652 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 21353652, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27873440).

21353652 is an abundant number, since it is smaller than the sum of its proper divisors (34393228).

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

21353652 is a wasteful number, since it uses less digits than its factorization.

21353652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1389 (or 1381 counting only the distinct ones).

The product of its digits is 5400, while the sum is 27.

The square root of 21353652 is about 4621.0011902184. The cubic root of 21353652 is about 277.4325329045.

Adding to 21353652 its reverse (25635312), we get a palindrome (46988964).

The spelling of 21353652 in words is "twenty-one million, three hundred fifty-three thousand, six hundred fifty-two".