121220111221554 has 32 divisors (see below), whose sum is σ = 264000242232000. Its totient is φ = 36960033910464.

The previous prime is 121220111221553. The next prime is 121220111221591. The reversal of 121220111221554 is 455122111022121.

It is not an unprimeable number, because it can be changed into a prime (121220111221553) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18333346849 + ... + 18333353460.

It is an arithmetic number, because the mean of its divisors is an integer number (8250007569750).

Almost surely, 2^{121220111221554} is an apocalyptic number.

121220111221554 is an abundant number, since it is smaller than the sum of its proper divisors (142780131010446).

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

121220111221554 is a wasteful number, since it uses less digits than its factorization.

121220111221554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36666700362.

The product of its (nonzero) digits is 3200, while the sum is 30.

Adding to 121220111221554 its reverse (455122111022121), we get a palindrome (576342222243675).

The spelling of 121220111221554 in words is "one hundred twenty-one trillion, two hundred twenty billion, one hundred eleven million, two hundred twenty-one thousand, five hundred fifty-four".