121815181280 has 192 divisors, whose sum is σ = 316300723200. Its totient is φ = 44061788160.

The previous prime is 121815181277. The next prime is 121815181333. The reversal of 121815181280 is 82181518121.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21523091 + ... + 21528749.

It is an arithmetic number, because the mean of its divisors is an integer number (1647399600).

Almost surely, 2^121815181280 is an apocalyptic number.

121815181280 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 121815181280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158150361600).

121815181280 is an abundant number, since it is smaller than the sum of its proper divisors (194485541920).

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

121815181280 is a wasteful number, since it uses less digits than its factorization.

121815181280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5897 (or 5889 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 38.

The spelling of 121815181280 in words is "one hundred twenty-one billion, eight hundred fifteen million, one hundred eighty-one thousand, two hundred eighty".