21353628 has 48 divisors (see below), whose sum is σ = 52778880. Its totient is φ = 6707904.

The previous prime is 21353627. The next prime is 21353639. The reversal of 21353628 is 82635312.

It is a junction number, because it is equal to n+sod(n) for n = 21353595 and 21353604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21353627) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14251 + ... + 15677.

It is an arithmetic number, because the mean of its divisors is an integer number (1099560).

Almost surely, 2^21353628 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 21353628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26389440).

21353628 is an abundant number, since it is smaller than the sum of its proper divisors (31425252).

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

21353628 is a wasteful number, since it uses less digits than its factorization.

21353628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1506 (or 1504 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

The square root of 21353628 is about 4620.9985933778. The cubic root of 21353628 is about 277.4324289662.

The spelling of 21353628 in words is "twenty-one million, three hundred fifty-three thousand, six hundred twenty-eight".