21549834 has 16 divisors (see below), whose sum is σ = 47888640. Its totient is φ = 7183260.

The previous prime is 21549833. The next prime is 21549839. The reversal of 21549834 is 43894512.

It is not an unprimeable number, because it can be changed into a prime (21549833) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 199482 + ... + 199589.

It is an arithmetic number, because the mean of its divisors is an integer number (2993040).

Almost surely, 2^21549834 is an apocalyptic number.

21549834 is an abundant number, since it is smaller than the sum of its proper divisors (26338806).

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

21549834 is a wasteful number, since it uses less digits than its factorization.

21549834 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399082 (or 399076 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 21549834 is about 4642.1798758773. The cubic root of 21549834 is about 278.2795610880.

The spelling of 21549834 in words is "twenty-one million, five hundred forty-nine thousand, eight hundred thirty-four".