121111211111100 has 144 divisors (see below), whose sum is σ = 400531106035200. Its totient is φ = 27678643096320.

The previous prime is 121111211111081. The next prime is 121111211111117. The reversal of 121111211111100 is 1111112111121.

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 121111211111100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10765681 + ... + 18924119.

Almost surely, 2^{121111211111100} is an apocalyptic number.

121111211111100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121111211111100 is an abundant number, since it is smaller than the sum of its proper divisors (279419894924100).

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

121111211111100 is a wasteful number, since it uses less digits than its factorization.

121111211111100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8165532 (or 8165525 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 15.

Adding to 121111211111100 its reverse (1111112111121), we get a palindrome (122222323222221).

The spelling of 121111211111100 in words is "one hundred twenty-one trillion, one hundred eleven billion, two hundred eleven million, one hundred eleven thousand, one hundred".