12121205688 has 64 divisors (see below), whose sum is σ = 33680256000. Its totient is φ = 4039173216.

The previous prime is 12121205687. The next prime is 12121205699. The reversal of 12121205688 is 88650212121.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121205687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 954243 + ... + 966861.

It is an arithmetic number, because the mean of its divisors is an integer number (526254000).

Almost surely, 2^12121205688 is an apocalyptic number.

12121205688 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

12121205688 is an abundant number, since it is smaller than the sum of its proper divisors (21559050312).

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

12121205688 is a wasteful number, since it uses less digits than its factorization.

12121205688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17081 (or 17071 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The spelling of 12121205688 in words is "twelve billion, one hundred twenty-one million, two hundred five thousand, six hundred eighty-eight".