121311554144 has 96 divisors (see below), whose sum is σ = 266378069664. Its totient is φ = 53914132480.

The previous prime is 121311554129. The next prime is 121311554153. The reversal of 121311554144 is 441455113121.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a self number, because there is not a number n which added to its sum of digits gives 121311554144.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5455112 + ... + 5477304.

It is an arithmetic number, because the mean of its divisors is an integer number (2774771559).

Almost surely, 2^121311554144 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121311554144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133189034832).

121311554144 is an abundant number, since it is smaller than the sum of its proper divisors (145066515520).

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

121311554144 is a wasteful number, since it uses less digits than its factorization.

121311554144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22560 (or 22552 counting only the distinct ones).

The product of its digits is 9600, while the sum is 32.

Adding to 121311554144 its reverse (441455113121), we get a palindrome (562766667265).

The spelling of 121311554144 in words is "one hundred twenty-one billion, three hundred eleven million, five hundred fifty-four thousand, one hundred forty-four".