21089004 has 12 divisors (see below), whose sum is σ = 49207704. Its totient is φ = 7029664.

The previous prime is 21088997. The next prime is 21089009. The reversal of 21089004 is 40098012.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (21089009) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 878697 + ... + 878720.

It is an arithmetic number, because the mean of its divisors is an integer number (4100642).

Almost surely, 2^21089004 is an apocalyptic number.

It is an amenable number.

21089004 is an abundant number, since it is smaller than the sum of its proper divisors (28118700).

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

21089004 is a wasteful number, since it uses less digits than its factorization.

21089004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1757424 (or 1757422 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 21089004 is about 4592.2765596162. The cubic root of 21089004 is about 276.2816385759.

The spelling of 21089004 in words is "twenty-one million, eighty-nine thousand, four".