1221110110 has 64 divisors (see below), whose sum is σ = 2458874880. Its totient is φ = 432881280.

The previous prime is 1221110101. The next prime is 1221110123. The reversal of 1221110110 is 110111221.

It is a super-2 number, since 2×1221110110² = 2982219801488424200, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 720424 + ... + 722116.

It is an arithmetic number, because the mean of its divisors is an integer number (38419920).

Almost surely, 2^1221110110 is an apocalyptic number.

1221110110 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221110110 is an abundant number, since it is smaller than the sum of its proper divisors (1237764770).

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

1221110110 is a wasteful number, since it uses less digits than its factorization.

1221110110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1873.

The product of its (nonzero) digits is 4, while the sum is 10.

The square root of 1221110110 is about 34944.3859582623. The cubic root of 1221110110 is about 1068.8537263074.

Adding to 1221110110 its reverse (110111221), we get a palindrome (1331221331).

The spelling of 1221110110 in words is "one billion, two hundred twenty-one million, one hundred ten thousand, one hundred ten".