1221000000120 has 384 divisors, whose sum is σ = 4231427428800. Its totient is φ = 304804749312.

The previous prime is 1221000000079. The next prime is 1221000000151. The reversal of 1221000000120 is 210000001221.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 61492114 + ... + 61511966.

Almost surely, 2^{1221000000120} is an apocalyptic number.

1221000000120 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 1221000000120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2115713714400).

1221000000120 is an abundant number, since it is smaller than the sum of its proper divisors (3010427428680).

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

1221000000120 is a wasteful number, since it uses less digits than its factorization.

1221000000120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20079 (or 20072 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 1221000000120 its reverse (210000001221), we get a palindrome (1431000001341).

The spelling of 1221000000120 in words is "one trillion, two hundred twenty-one billion, one hundred twenty", and thus it is an aban number.