21493528 has 16 divisors (see below), whose sum is σ = 46057680. Its totient is φ = 9211488.

The previous prime is 21493517. The next prime is 21493531. The reversal of 21493528 is 82539412.

It is a junction number, because it is equal to n+sod(n) for n = 21493493 and 21493502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 191851 + ... + 191962.

It is an arithmetic number, because the mean of its divisors is an integer number (2878605).

Almost surely, 2^21493528 is an apocalyptic number.

21493528 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21493528 is an abundant number, since it is smaller than the sum of its proper divisors (24564152).

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

21493528 is a wasteful number, since it uses less digits than its factorization.

21493528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 383826 (or 383822 counting only the distinct ones).

The product of its digits is 17280, while the sum is 34.

The square root of 21493528 is about 4636.1113015112. Note that the first 3 decimals coincide. The cubic root of 21493528 is about 278.0369841933.

The spelling of 21493528 in words is "twenty-one million, four hundred ninety-three thousand, five hundred twenty-eight".