21212320110 has 32 divisors (see below), whose sum is σ = 52093514880. Its totient is φ = 5525069088.

The previous prime is 21212320093. The next prime is 21212320139. The reversal of 21212320110 is 1102321212.

It is a super-2 number, since 2×21212320110² (a number of 21 digits) contains 22 as substring.

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 21212320110.

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 15 ways as a sum of consecutive naturals, for example, 8220540 + ... + 8223119.

It is an arithmetic number, because the mean of its divisors is an integer number (1627922340).

Almost surely, 2^21212320110 is an apocalyptic number.

21212320110 is an abundant number, since it is smaller than the sum of its proper divisors (30881194770).

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

21212320110 is a wasteful number, since it uses less digits than its factorization.

21212320110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16443712.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21212320110 its reverse (1102321212), we get a palindrome (22314641322).

The spelling of 21212320110 in words is "twenty-one billion, two hundred twelve million, three hundred twenty thousand, one hundred ten".