21089994 has 16 divisors (see below), whose sum is σ = 42239232. Its totient is φ = 7020128.

The previous prime is 21089993. The next prime is 21090007. The reversal of 21089994 is 49998012.

It is not an unprimeable number, because it can be changed into a prime (21089993) 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, 3142 + ... + 7214.

It is an arithmetic number, because the mean of its divisors is an integer number (2639952).

Almost surely, 2^21089994 is an apocalyptic number.

21089994 is an abundant number, since it is smaller than the sum of its proper divisors (21149238).

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

21089994 is a wasteful number, since it uses less digits than its factorization.

21089994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4941.

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 21089994 is about 4592.3843480266. The cubic root of 21089994 is about 276.2859617537.

The spelling of 21089994 in words is "twenty-one million, eighty-nine thousand, nine hundred ninety-four".