21089106 has 16 divisors (see below), whose sum is σ = 46864800. Its totient is φ = 7029684.

The previous prime is 21089093. The next prime is 21089111. The reversal of 21089106 is 60198012.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 21089106.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 195216 + ... + 195323.

It is an arithmetic number, because the mean of its divisors is an integer number (2929050).

Almost surely, 2^21089106 is an apocalyptic number.

21089106 is an abundant number, since it is smaller than the sum of its proper divisors (25775694).

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

21089106 is a wasteful number, since it uses less digits than its factorization.

21089106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390550 (or 390544 counting only the distinct ones).

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

The square root of 21089106 is about 4592.2876652057. The cubic root of 21089106 is about 276.2820840004.

The spelling of 21089106 in words is "twenty-one million, eighty-nine thousand, one hundred six".