121321320 has 128 divisors (see below), whose sum is σ = 384134400. Its totient is φ = 30593024.

The previous prime is 121321307. The next prime is 121321339. The reversal of 121321320 is 23123121.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 121321320.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 311686 + ... + 312074.

It is an arithmetic number, because the mean of its divisors is an integer number (3001050).

Almost surely, 2^121321320 is an apocalyptic number.

121321320 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 121321320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (192067200).

121321320 is an abundant number, since it is smaller than the sum of its proper divisors (262813080).

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

121321320 is a wasteful number, since it uses less digits than its factorization.

121321320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 539 (or 535 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 121321320 is about 11014.5957710667. The cubic root of 121321320 is about 495.0461746539.

Adding to 121321320 its reverse (23123121), we get a palindrome (144444441).

The spelling of 121321320 in words is "one hundred twenty-one million, three hundred twenty-one thousand, three hundred twenty".