12123121320 has 48 divisors (see below), whose sum is σ = 39400145460. Its totient is φ = 3232832256.

The previous prime is 12123121319. The next prime is 12123121331. The reversal of 12123121320 is 2312132121.

It can be written as a sum of positive squares in 2 ways, for example, as 12099560004 + 23561316 = 109998^2 + 4854^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 12123121293 and 12123121302.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16837309 + ... + 16838028.

Almost surely, 2^12123121320 is an apocalyptic number.

12123121320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12123121320 is an abundant number, since it is smaller than the sum of its proper divisors (27277024140).

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

12123121320 is a wasteful number, since it uses less digits than its factorization.

12123121320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33675354 (or 33675347 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 12123121320 its reverse (2312132121), we get a palindrome (14435253441).

The spelling of 12123121320 in words is "twelve billion, one hundred twenty-three million, one hundred twenty-one thousand, three hundred twenty".