1221211110 has 32 divisors (see below), whose sum is σ = 3349608192. Its totient is φ = 279133920.

The previous prime is 1221211067. The next prime is 1221211127. The reversal of 1221211110 is 111121221.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2907436 + ... + 2907855.

It is an arithmetic number, because the mean of its divisors is an integer number (104675256).

Almost surely, 2^1221211110 is an apocalyptic number.

1221211110 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221211110 is an abundant number, since it is smaller than the sum of its proper divisors (2128397082).

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

1221211110 is a wasteful number, since it uses less digits than its factorization.

1221211110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5815308.

The product of its (nonzero) digits is 8, while the sum is 12.

The square root of 1221211110 is about 34945.8310818329. The cubic root of 1221211110 is about 1068.8831943707.

Adding to 1221211110 its reverse (111121221), we get a palindrome (1332332331).

The spelling of 1221211110 in words is "one billion, two hundred twenty-one million, two hundred eleven thousand, one hundred ten".