121111000020 has 72 divisors (see below), whose sum is σ = 380037981960. Its totient is φ = 31182600960.

The previous prime is 121111000009. The next prime is 121111000051. The reversal of 121111000020 is 20000111121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 7156144836 + 113954855184 = 84594^2 + 337572^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 121110999966 and 121111000011.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11595451 + ... + 11605890.

It is an arithmetic number, because the mean of its divisors is an integer number (5278305305).

Almost surely, 2^121111000020 is an apocalyptic number.

121111000020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121111000020 is an abundant number, since it is smaller than the sum of its proper divisors (258926981940).

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

121111000020 is a wasteful number, since it uses less digits than its factorization.

121111000020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23201385 (or 23201380 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 121111000020 its reverse (20000111121), we get a palindrome (141111111141).

The spelling of 121111000020 in words is "one hundred twenty-one billion, one hundred eleven million, twenty", and thus it is an aban number.