121000000000 has 300 divisors, whose sum is σ = 332175258954. Its totient is φ = 44000000000.

The previous prime is 120999999959. The next prime is 121000000021. The reversal of 121000000000 is 121.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 5 ways, for example, as 113833361664 + 7166638336 = 337392^2 + 84656^2 .

It is a Harshad number since it is a multiple of its sum of digits (4).

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 10999999995 + ... + 11000000005.

Almost surely, 2^121000000000 is an apocalyptic number.

121000000000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121000000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (166087629477).

121000000000 is an abundant number, since it is smaller than the sum of its proper divisors (211175258954).

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

121000000000 is an frugal number, since it uses more digits than its factorization.

121000000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85 (or 18 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 4.

Adding to 121000000000 its reverse (121), we get a palindrome (121000000121).

121000000000 divided by its reverse (121) gives a 9-th power (1000000000 = 10⁹).

The spelling of 121000000000 in words is "one hundred twenty-one billion", and thus it is an aban number.