121665238555080 has 256 divisors, whose sum is σ = 411139788595200. Its totient is φ = 28534954752000.

The previous prime is 121665238555079. The next prime is 121665238555093. The reversal of 121665238555080 is 80555832566121.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 121665238555080.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 142425876 + ... + 143277564.

It is an arithmetic number, because the mean of its divisors is an integer number (1606014799200).

Almost surely, 2^{121665238555080} is an apocalyptic number.

121665238555080 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 121665238555080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (205569894297600).

121665238555080 is an abundant number, since it is smaller than the sum of its proper divisors (289474550040120).

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

121665238555080 is a wasteful number, since it uses less digits than its factorization.

121665238555080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 855236 (or 855232 counting only the distinct ones).

The product of its (nonzero) digits is 17280000, while the sum is 57.

The spelling of 121665238555080 in words is "one hundred twenty-one trillion, six hundred sixty-five billion, two hundred thirty-eight million, five hundred fifty-five thousand, eighty".