21010785 has 16 divisors (see below), whose sum is σ = 34188480. Its totient is φ = 11015360.

The previous prime is 21010763. The next prime is 21010811. The reversal of 21010785 is 58701012.

It is not a de Polignac number, because 21010785 - 2⁶ = 21010721 is a prime.

It is an alternating number because its digits alternate between even and odd.

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, 10986 + ... + 12755.

It is an arithmetic number, because the mean of its divisors is an integer number (2136780).

Almost surely, 2^21010785 is an apocalyptic number.

It is an amenable number.

21010785 is a deficient number, since it is larger than the sum of its proper divisors (13177695).

21010785 is a wasteful number, since it uses less digits than its factorization.

21010785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23808.

The product of its (nonzero) digits is 560, while the sum is 24.

The square root of 21010785 is about 4583.7522838827. The cubic root of 21010785 is about 275.9396397094.

Adding to 21010785 its reverse (58701012), we get a palindrome (79711797).

The spelling of 21010785 in words is "twenty-one million, ten thousand, seven hundred eighty-five".