121819288500 has 1536 divisors, whose sum is σ = 542442700800. Its totient is φ = 22842777600.

The previous prime is 121819288499. The next prime is 121819288529. The reversal of 121819288500 is 5882918121.

121819288500 is a `hidden beast` number, since 121 + 8 + 19 + 2 + 8 + 8 + 500 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 511 ways as a sum of consecutive naturals, for example, 396805347 + ... + 396805653.

It is an arithmetic number, because the mean of its divisors is an integer number (353152800).

Almost surely, 2^121819288500 is an apocalyptic number.

121819288500 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 121819288500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (271221350400).

121819288500 is an abundant number, since it is smaller than the sum of its proper divisors (420623412300).

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

121819288500 is a wasteful number, since it uses less digits than its factorization.

121819288500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 391 (or 373 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 45.

The spelling of 121819288500 in words is "one hundred twenty-one billion, eight hundred nineteen million, two hundred eighty-eight thousand, five hundred".