1212120100 has 36 divisors (see below), whose sum is σ = 2634300144. Its totient is φ = 484110880.

The previous prime is 1212120097. The next prime is 1212120109. The reversal of 1212120100 is 10212121.

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

It is not an unprimeable number, because it can be changed into a prime (1212120109) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 59427 + ... + 77173.

It is an arithmetic number, because the mean of its divisors is an integer number (73175004).

Almost surely, 2^1212120100 is an apocalyptic number.

1212120100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1212120100 is an abundant number, since it is smaller than the sum of its proper divisors (1422180044).

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

1212120100 is a wasteful number, since it uses less digits than its factorization.

1212120100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18444 (or 18437 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 1212120100 is about 34815.5152195110. The cubic root of 1212120100 is about 1066.2242381743.

Adding to 1212120100 its reverse (10212121), we get a palindrome (1222332221).

The spelling of 1212120100 in words is "one billion, two hundred twelve million, one hundred twenty thousand, one hundred".