121421811840 has 1152 divisors, whose sum is σ = 498813292800. Its totient is φ = 24958402560.

The previous prime is 121421811839. The next prime is 121421811877. The reversal of 121421811840 is 48118124121.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1536984921 + ... + 1536984999.

It is an arithmetic number, because the mean of its divisors is an integer number (432997650).

Almost surely, 2^121421811840 is an apocalyptic number.

121421811840 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 121421811840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (249406646400).

121421811840 is an abundant number, since it is smaller than the sum of its proper divisors (377391480960).

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

121421811840 is a wasteful number, since it uses less digits than its factorization.

121421811840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194 (or 144 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 33.

Adding to 121421811840 its reverse (48118124121), we get a palindrome (169539935961).

The spelling of 121421811840 in words is "one hundred twenty-one billion, four hundred twenty-one million, eight hundred eleven thousand, eight hundred forty".