1212121110 has 64 divisors (see below), whose sum is σ = 2993982912. Its totient is φ = 313837056.

The previous prime is 1212121069. The next prime is 1212121121. The reversal of 1212121110 is 111212121.

1212121110 = 2788² + 2789² + ... + 2935².

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, 750664 + ... + 752276.

It is an arithmetic number, because the mean of its divisors is an integer number (46780983).

Almost surely, 2^1212121110 is an apocalyptic number.

1212121110 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1212121110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1496991456).

1212121110 is an abundant number, since it is smaller than the sum of its proper divisors (1781861802).

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

1212121110 is a wasteful number, since it uses less digits than its factorization.

1212121110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2337.

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

The square root of 1212121110 is about 34815.5297245353. The cubic root of 1212121110 is about 1066.2245343183.

Adding to 1212121110 its reverse (111212121), we get a palindrome (1323333231).

The spelling of 1212121110 in words is "one billion, two hundred twelve million, one hundred twenty-one thousand, one hundred ten".