121205400 has 96 divisors (see below), whose sum is σ = 392117760. Its totient is φ = 30912640.

The previous prime is 121205323. The next prime is 121205401. The reversal of 121205400 is 4502121.

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 121205400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121205401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9409 + ... + 18191.

It is an arithmetic number, because the mean of its divisors is an integer number (4084560).

Almost surely, 2^121205400 is an apocalyptic number.

121205400 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 121205400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (196058880).

121205400 is an abundant number, since it is smaller than the sum of its proper divisors (270912360).

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

121205400 is a wasteful number, since it uses less digits than its factorization.

121205400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8825 (or 8816 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 121205400 is about 11009.3324048282. The cubic root of 121205400 is about 494.8884556335. Note that the first 3 decimals are identical.

Adding to 121205400 its reverse (4502121), we get a palindrome (125707521).

The spelling of 121205400 in words is "one hundred twenty-one million, two hundred five thousand, four hundred".