21013040220 has 24 divisors (see below), whose sum is σ = 58836512784. Its totient is φ = 5603477376.

The previous prime is 21013040207. The next prime is 21013040287. The reversal of 21013040220 is 2204031012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21013040220.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175108609 + ... + 175108728.

It is an arithmetic number, because the mean of its divisors is an integer number (2451521366).

Almost surely, 2^21013040220 is an apocalyptic number.

21013040220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21013040220 is an abundant number, since it is smaller than the sum of its proper divisors (37823472564).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21013040220 is a wasteful number, since it uses less digits than its factorization.

21013040220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350217349 (or 350217347 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

Adding to 21013040220 its reverse (2204031012), we get a palindrome (23217071232).

The spelling of 21013040220 in words is "twenty-one billion, thirteen million, forty thousand, two hundred twenty".