121515402144 has 48 divisors (see below), whose sum is σ = 337741342848. Its totient is φ = 38122478592.

The previous prime is 121515402143. The next prime is 121515402157. The reversal of 121515402144 is 441204515121.

121515402144 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (48).

It is not an unprimeable number, because it can be changed into a prime (121515402143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37227352 + ... + 37230615.

It is an arithmetic number, because the mean of its divisors is an integer number (7036277976).

Almost surely, 2^121515402144 is an apocalyptic number.

It is an amenable number.

121515402144 is an abundant number, since it is smaller than the sum of its proper divisors (216225940704).

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

121515402144 is a wasteful number, since it uses less digits than its factorization.

121515402144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74457997 (or 74457989 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 30.

Adding to 121515402144 its reverse (441204515121), we get a palindrome (562719917265).

The spelling of 121515402144 in words is "one hundred twenty-one billion, five hundred fifteen million, four hundred two thousand, one hundred forty-four".