1221111110 has 8 divisors (see below), whose sum is σ = 2198000016. Its totient is φ = 488444440.

The previous prime is 1221111097. The next prime is 1221111167. The reversal of 1221111110 is 111111221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×1221111110² = 2982224685930864200, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1221111091 and 1221111100.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61055546 + ... + 61055565.

It is an arithmetic number, because the mean of its divisors is an integer number (274750002).

Almost surely, 2^1221111110 is an apocalyptic number.

1221111110 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221111110 is a deficient number, since it is larger than the sum of its proper divisors (976888906).

1221111110 is a wasteful number, since it uses less digits than its factorization.

1221111110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122111118.

The product of its (nonzero) digits is 4, while the sum is 11.

The square root of 1221111110 is about 34944.4002667094. The cubic root of 1221111110 is about 1068.8540180783.

Adding to 1221111110 its reverse (111111221), we get a palindrome (1332222331).

It can be divided in two parts, 1221111 and 110, that added together give a palindrome (1221221).

The spelling of 1221111110 in words is "one billion, two hundred twenty-one million, one hundred eleven thousand, one hundred ten".