1212121111200 has 72 divisors (see below), whose sum is σ = 3945454224768. Its totient is φ = 323232295680.

The previous prime is 1212121111199. The next prime is 1212121111211. The reversal of 1212121111200 is 21111212121.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1212121111200.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 252522832 + ... + 252527631.

It is an arithmetic number, because the mean of its divisors is an integer number (54797975344).

Almost surely, 2^{1212121111200} is an apocalyptic number.

1212121111200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1212121111200 is an abundant number, since it is smaller than the sum of its proper divisors (2733333113568).

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

1212121111200 is a wasteful number, since it uses less digits than its factorization.

1212121111200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505050486 (or 505050473 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1212121111200 its reverse (21111212121), we get a palindrome (1233232323321).

The spelling of 1212121111200 in words is "one trillion, two hundred twelve billion, one hundred twenty-one million, one hundred eleven thousand, two hundred".