121024128128 has 72 divisors (see below), whose sum is σ = 244384897995. Its totient is φ = 59699306496.

The previous prime is 121024128109. The next prime is 121024128139. The reversal of 121024128128 is 821821420121.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 5 ways, for example, as 4218762304 + 116805365824 = 64952^2 + 341768^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=245992.

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

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121024128094 and 121024128103.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 381779426 + ... + 381779742.

Almost surely, 2^121024128128 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 121024128128

121024128128 is an abundant number, since it is smaller than the sum of its proper divisors (123360769867).

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

121024128128 is an frugal number, since it uses more digits than its factorization.

121024128128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 842 (or 416 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 32.

Multiplying 121024128128 by its sum of digits (32), we get a square (3872772100096 = 1967936²).

121024128128 divided by its sum of digits (32) gives a square (3782004004 = 61498²).

Adding to 121024128128 its reverse (821821420121), we get a palindrome (942845548249).

The spelling of 121024128128 in words is "one hundred twenty-one billion, twenty-four million, one hundred twenty-eight thousand, one hundred twenty-eight".