123121312 has 24 divisors (see below), whose sum is σ = 242797716. Its totient is φ = 61458432.

The previous prime is 123121309. The next prime is 123121333. The reversal of 123121312 is 213121321.

It can be written as a sum of positive squares in 2 ways, for example, as 122855056 + 266256 = 11084^2 + 516^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18678 + ... + 24394.

Almost surely, 2^123121312 is an apocalyptic number.

It is an amenable number.

123121312 is a deficient number, since it is larger than the sum of its proper divisors (119676404).

123121312 is an equidigital number, since it uses as much as digits as its factorization.

123121312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6400 (or 6392 counting only the distinct ones).

The product of its digits is 72, while the sum is 16.

The square root of 123121312 is about 11096.0043258824. The cubic root of 123121312 is about 497.4824276008.

Adding to 123121312 its reverse (213121321), we get a palindrome (336242633).

Subtracting 123121312 from its reverse (213121321), we obtain a palindrome (90000009).

The spelling of 123121312 in words is "one hundred twenty-three million, one hundred twenty-one thousand, three hundred twelve".