21089016 has 48 divisors (see below), whose sum is σ = 61512360. Its totient is φ = 6488640.

The previous prime is 21089011. The next prime is 21089051. The reversal of 21089016 is 61098012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21089011) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10330 + ... + 12201.

Almost surely, 2^21089016 is an apocalyptic number.

21089016 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21089016 is an abundant number, since it is smaller than the sum of its proper divisors (40423344).

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

21089016 is a wasteful number, since it uses less digits than its factorization.

21089016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22556 (or 22549 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 21089016 is about 4592.2778661575. The cubic root of 21089016 is about 276.2816909788.

The spelling of 21089016 in words is "twenty-one million, eighty-nine thousand, sixteen".