21403085 has 24 divisors (see below), whose sum is σ = 29905848. Its totient is φ = 14643200.

The previous prime is 21403079. The next prime is 21403097. The reversal of 21403085 is 58030412.

It can be written as a sum of positive squares in 4 ways, for example, as 3374569 + 18028516 = 1837^2 + 4246^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21403085 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21403085.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 9245 + ... + 11325.

It is an arithmetic number, because the mean of its divisors is an integer number (1246077).

Almost surely, 2^21403085 is an apocalyptic number.

It is an amenable number.

21403085 is a deficient number, since it is larger than the sum of its proper divisors (8502763).

21403085 is a wasteful number, since it uses less digits than its factorization.

21403085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2125 (or 2114 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21403085 is about 4626.3468309239. The cubic root of 21403085 is about 277.6464503061.

Adding to 21403085 its reverse (58030412), we get a palindrome (79433497).

It can be divided in two parts, 2140 and 3085, that added together give a palindrome (5225).

The spelling of 21403085 in words is "twenty-one million, four hundred three thousand, eighty-five".