121221201000 has 256 divisors, whose sum is σ = 395812085760. Its totient is φ = 30829497600.

The previous prime is 121221200987. The next prime is 121221201001. The reversal of 121221201000 is 102122121.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (121221201001) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 25320607 + ... + 25325393.

It is an arithmetic number, because the mean of its divisors is an integer number (1546140960).

Almost surely, 2^121221201000 is an apocalyptic number.

121221201000 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 121221201000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (197906042880).

121221201000 is an abundant number, since it is smaller than the sum of its proper divisors (274590884760).

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

121221201000 is a wasteful number, since it uses less digits than its factorization.

121221201000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5201 (or 5187 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 121221201000 its reverse (102122121), we get a palindrome (121323323121).

The spelling of 121221201000 in words is "one hundred twenty-one billion, two hundred twenty-one million, two hundred one thousand".