121111111020 has 48 divisors (see below), whose sum is σ = 339421551840. Its totient is φ = 32266730496.

The previous prime is 121111111007. The next prime is 121111111021. The reversal of 121111111020 is 20111111121.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 121111110987 and 121111111005.

It is not an unprimeable number, because it can be changed into a prime (121111111021) 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, 857805 + ... + 988964.

It is an arithmetic number, because the mean of its divisors is an integer number (7071282330).

Almost surely, 2^121111111020 is an apocalyptic number.

121111111020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121111111020 is an abundant number, since it is smaller than the sum of its proper divisors (218310440820).

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

121111111020 is a wasteful number, since it uses less digits than its factorization.

121111111020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1847874 (or 1847872 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 121111111020 its reverse (20111111121), we get a palindrome (141222222141).

The spelling of 121111111020 in words is "one hundred twenty-one billion, one hundred eleven million, one hundred eleven thousand, twenty".