21120785 has 16 divisors (see below), whose sum is σ = 30226176. Its totient is φ = 13852608.

The previous prime is 21120773. The next prime is 21120793. The reversal of 21120785 is 58702112.

It is not a de Polignac number, because 21120785 - 2⁴ = 21120769 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12314 + ... + 13923.

It is an arithmetic number, because the mean of its divisors is an integer number (1889136).

Almost surely, 2^21120785 is an apocalyptic number.

It is an amenable number.

21120785 is a deficient number, since it is larger than the sum of its proper divisors (9105391).

21120785 is a wasteful number, since it uses less digits than its factorization.

21120785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26272.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 21120785 is about 4595.7355232868. The cubic root of 21120785 is about 276.4203538311.

Adding to 21120785 its reverse (58702112), we get a palindrome (79822897).

The spelling of 21120785 in words is "twenty-one million, one hundred twenty thousand, seven hundred eighty-five".