21085030 has 16 divisors (see below), whose sum is σ = 39262320. Its totient is φ = 8143072.

The previous prime is 21084989. The next prime is 21085033. The reversal of 21085030 is 3058012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21084989 and 21085007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21085033) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36064 + ... + 36643.

It is an arithmetic number, because the mean of its divisors is an integer number (2453895).

Almost surely, 2^21085030 is an apocalyptic number.

21085030 is a deficient number, since it is larger than the sum of its proper divisors (18177290).

21085030 is a wasteful number, since it uses less digits than its factorization.

21085030 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72743.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 21085030 is about 4591.8438562303. The cubic root of 21085030 is about 276.2642833670.

The spelling of 21085030 in words is "twenty-one million, eighty-five thousand, thirty".