1221221110 has 32 divisors (see below), whose sum is σ = 2295786240. Its totient is φ = 466839648.

The previous prime is 1221221093. The next prime is 1221221119. The reversal of 1221221110 is 111221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221221119) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 453829 + ... + 456511.

It is an arithmetic number, because the mean of its divisors is an integer number (71743320).

Almost surely, 2^1221221110 is an apocalyptic number.

1221221110 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221221110 is a deficient number, since it is larger than the sum of its proper divisors (1074565130).

1221221110 is a wasteful number, since it uses less digits than its factorization.

1221221110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4692.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 1221221110 is about 34945.9741601232. The cubic root of 1221221110 is about 1068.8861119123.

Adding to 1221221110 its reverse (111221221), we get a palindrome (1332442331).

The spelling of 1221221110 in words is "one billion, two hundred twenty-one million, two hundred twenty-one thousand, one hundred ten".