21013010685 has 48 divisors (see below), whose sum is σ = 38390876160. Its totient is φ = 11023179840.

The previous prime is 21013010663. The next prime is 21013010719. The reversal of 21013010685 is 58601031012.

It is not a de Polignac number, because 21013010685 - 2²¹ = 21010913533 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 67645 + ... + 215874.

It is an arithmetic number, because the mean of its divisors is an integer number (799809920).

Almost surely, 2^21013010685 is an apocalyptic number.

It is an amenable number.

21013010685 is a deficient number, since it is larger than the sum of its proper divisors (17377865475).

21013010685 is an equidigital number, since it uses as much as digits as its factorization.

21013010685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283600 (or 283588 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

Adding to 21013010685 its reverse (58601031012), we get a palindrome (79614041697).

The spelling of 21013010685 in words is "twenty-one billion, thirteen million, ten thousand, six hundred eighty-five".