21010084 has 12 divisors (see below), whose sum is σ = 36831564. Its totient is φ = 10486784.

The previous prime is 21010069. The next prime is 21010097. The reversal of 21010084 is 48001012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 10705984 + 10304100 = 3272^2 + 3210^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1789 + ... + 6724.

It is an arithmetic number, because the mean of its divisors is an integer number (3069297).

Almost surely, 2^21010084 is an apocalyptic number.

It is an amenable number.

21010084 is a deficient number, since it is larger than the sum of its proper divisors (15821480).

21010084 is a wasteful number, since it uses less digits than its factorization.

21010084 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9134 (or 9132 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 21010084 is about 4583.6758175072. The cubic root of 21010084 is about 275.9365708753.

Adding to 21010084 its reverse (48001012), we get a palindrome (69011096).

It can be divided in two parts, 2101008 and 4, that added together give a palindrome (2101012).

The spelling of 21010084 in words is "twenty-one million, ten thousand, eighty-four".