123121131012 has 36 divisors (see below), whose sum is σ = 339515847216. Its totient is φ = 37309433520.

The previous prime is 123121130929. The next prime is 123121131167. The reversal of 123121131012 is 210131121321.

It is a tau number, because it is divible by the number of its divisors (36).

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

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, 155455578 + ... + 155456369.

It is an arithmetic number, because the mean of its divisors is an integer number (9430995756).

Almost surely, 2^123121131012 is an apocalyptic number.

123121131012 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

123121131012 is an abundant number, since it is smaller than the sum of its proper divisors (216394716204).

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

123121131012 is a wasteful number, since it uses less digits than its factorization.

123121131012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310911968 (or 310911963 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

Adding to 123121131012 its reverse (210131121321), we get a palindrome (333252252333).

The spelling of 123121131012 in words is "one hundred twenty-three billion, one hundred twenty-one million, one hundred thirty-one thousand, twelve".