121220111222100 has 432 divisors, whose sum is σ = 416942593966080. Its totient is φ = 29213843846400.

The previous prime is 121220111222069. The next prime is 121220111222131. The reversal of 121220111222100 is 1222111022121.

121220111222100 is a `hidden beast` number, since 1 + 212 + 20 + 111 + 222 + 100 = 666.

It is an interprime number because it is at equal distance from previous prime (121220111222069) and next prime (121220111222131).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1587298117 + ... + 1587374483.

It is an arithmetic number, because the mean of its divisors is an integer number (965144893440).

Almost surely, 2^{121220111222100} is an apocalyptic number.

121220111222100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121220111222100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (208471296983040).

121220111222100 is an abundant number, since it is smaller than the sum of its proper divisors (295722482743980).

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

121220111222100 is a wasteful number, since it uses less digits than its factorization.

121220111222100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77340 (or 77330 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 121220111222100 its reverse (1222111022121), we get a palindrome (122442222244221).

The spelling of 121220111222100 in words is "one hundred twenty-one trillion, two hundred twenty billion, one hundred eleven million, two hundred twenty-two thousand, one hundred".