21370085 has 16 divisors (see below), whose sum is σ = 28259712. Its totient is φ = 15384000.

The previous prime is 21370049. The next prime is 21370087. The reversal of 21370085 is 58007312.

It is not a de Polignac number, because 21370085 - 2⁶ = 21370021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21370087) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 3632 + ... + 7478.

It is an arithmetic number, because the mean of its divisors is an integer number (1766232).

Almost surely, 2^21370085 is an apocalyptic number.

It is an amenable number.

21370085 is a deficient number, since it is larger than the sum of its proper divisors (6889627).

21370085 is a wasteful number, since it uses less digits than its factorization.

21370085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3964.

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 21370085 is about 4622.7789261439. The cubic root of 21370085 is about 277.5036820116.

Adding to 21370085 its reverse (58007312), we get a palindrome (79377397).

The spelling of 21370085 in words is "twenty-one million, three hundred seventy thousand, eighty-five".