21110000001220 has 24 divisors (see below), whose sum is σ = 47741076926424. Its totient is φ = 7794461538816.

The previous prime is 21110000001191. The next prime is 21110000001263. The reversal of 21110000001220 is 2210000001112.

It can be written as a sum of positive squares in 4 ways, for example, as 3338784090756 + 17771215910464 = 1827234^2 + 4215592^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 21110000001197 and 21110000001206.

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, 40596153589 + ... + 40596154108.

It is an arithmetic number, because the mean of its divisors is an integer number (1989211538601).

Almost surely, 2^{21110000001220} is an apocalyptic number.

21110000001220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21110000001220 is an abundant number, since it is smaller than the sum of its proper divisors (26631076925204).

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

21110000001220 is a wasteful number, since it uses less digits than its factorization.

21110000001220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81192307719 (or 81192307717 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21110000001220 its reverse (2210000001112), we get a palindrome (23320000002332).

The spelling of 21110000001220 in words is "twenty-one trillion, one hundred ten billion, one thousand, two hundred twenty".