21542028 has 24 divisors (see below), whose sum is σ = 51090480. Its totient is φ = 7062720.

The previous prime is 21541979. The next prime is 21542063. The reversal of 21542028 is 82024512.

It is a junction number, because it is equal to n+sod(n) for n = 21541989 and 21542007.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13983 + ... + 15446.

It is an arithmetic number, because the mean of its divisors is an integer number (2128770).

Almost surely, 2^21542028 is an apocalyptic number.

It is an amenable number.

21542028 is an abundant number, since it is smaller than the sum of its proper divisors (29548452).

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

21542028 is a wasteful number, since it uses less digits than its factorization.

21542028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29497 (or 29495 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 21542028 is about 4641.3390309263. The cubic root of 21542028 is about 278.2459566127.

The spelling of 21542028 in words is "twenty-one million, five hundred forty-two thousand, twenty-eight".