21089946 has 16 divisors (see below), whose sum is σ = 42285600. Its totient is φ = 7012368.

The previous prime is 21089921. The next prime is 21089947. The reversal of 21089946 is 64998012.

It is not an unprimeable number, because it can be changed into a prime (21089947) 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, 1681 + ... + 6708.

It is an arithmetic number, because the mean of its divisors is an integer number (2642850).

Almost surely, 2^21089946 is an apocalyptic number.

21089946 is an abundant number, since it is smaller than the sum of its proper divisors (21195654).

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

21089946 is a wasteful number, since it uses less digits than its factorization.

21089946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8813.

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 21089946 is about 4592.3791219802. The cubic root of 21089946 is about 276.2857521482.

The spelling of 21089946 in words is "twenty-one million, eighty-nine thousand, nine hundred forty-six".