121221534500 has 192 divisors, whose sum is σ = 319106511360. Its totient is φ = 39683072000.

The previous prime is 121221534487. The next prime is 121221534521. The reversal of 121221534500 is 5435122121.

It is a self number, because there is not a number n which added to its sum of digits gives 121221534500.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2122316 + ... + 2178684.

It is an arithmetic number, because the mean of its divisors is an integer number (1662013080).

Almost surely, 2^121221534500 is an apocalyptic number.

121221534500 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 121221534500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (159553255680).

121221534500 is an abundant number, since it is smaller than the sum of its proper divisors (197884976860).

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

121221534500 is a wasteful number, since it uses less digits than its factorization.

121221534500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56439 (or 56427 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

Adding to 121221534500 its reverse (5435122121), we get a palindrome (126656656621).

The spelling of 121221534500 in words is "one hundred twenty-one billion, two hundred twenty-one million, five hundred thirty-four thousand, five hundred".