121812866640 has 240 divisors, whose sum is σ = 424648463616. Its totient is φ = 31270579200.

The previous prime is 121812866627. The next prime is 121812866647. The reversal of 121812866640 is 46668218121.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121812866647) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2034735 + ... + 2093745.

Almost surely, 2^121812866640 is an apocalyptic number.

121812866640 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 121812866640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (212324231808).

121812866640 is an abundant number, since it is smaller than the sum of its proper divisors (302835596976).

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

121812866640 is a wasteful number, since it uses less digits than its factorization.

121812866640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59138 (or 59129 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 45.

The spelling of 121812866640 in words is "one hundred twenty-one billion, eight hundred twelve million, eight hundred sixty-six thousand, six hundred forty".