121901778144 has 576 divisors, whose sum is σ = 397533007872. Its totient is φ = 36578304000.

The previous prime is 121901778143. The next prime is 121901778149. The reversal of 121901778144 is 441877109121.

It is a self number, because there is not a number n which added to its sum of digits gives 121901778144.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121901778143) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 618790654 + ... + 618790850.

It is an arithmetic number, because the mean of its divisors is an integer number (690161472).

Almost surely, 2^121901778144 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121901778144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (198766503936).

121901778144 is an abundant number, since it is smaller than the sum of its proper divisors (275631229728).

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

121901778144 is a wasteful number, since it uses less digits than its factorization.

121901778144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 421 (or 401 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 45.

The spelling of 121901778144 in words is "one hundred twenty-one billion, nine hundred one million, seven hundred seventy-eight thousand, one hundred forty-four".