1212100100 has 36 divisors (see below), whose sum is σ = 2647942500. Its totient is φ = 481580160.

The previous prime is 1212100067. The next prime is 1212100121. The reversal of 1212100100 is 10012121.

It can be written as a sum of positive squares in 6 ways, for example, as 515562436 + 696537664 = 22706^2 + 26392^2 .

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 11 ways as a sum of consecutive naturals, for example, 25775 + ... + 55574.

Almost surely, 2^1212100100 is an apocalyptic number.

1212100100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1212100100 is an abundant number, since it is smaller than the sum of its proper divisors (1435842400).

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

1212100100 is a wasteful number, since it uses less digits than its factorization.

1212100100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81512 (or 81505 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 1212100100 is about 34815.2279900620. The cubic root of 1212100100 is about 1066.2183739034.

Adding to 1212100100 its reverse (10012121), we get a palindrome (1222112221).

The spelling of 1212100100 in words is "one billion, two hundred twelve million, one hundred thousand, one hundred".