121220205 has 16 divisors (see below), whose sum is σ = 194579520. Its totient is φ = 64441728.

The previous prime is 121220201. The next prime is 121220213. The reversal of 121220205 is 502022121.

It is not a de Polignac number, because 121220205 - 2² = 121220201 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121220201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8215 + ... + 17604.

It is an arithmetic number, because the mean of its divisors is an integer number (12161220).

Almost surely, 2^121220205 is an apocalyptic number.

121220205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121220205 is a deficient number, since it is larger than the sum of its proper divisors (73359315).

121220205 is a wasteful number, since it uses less digits than its factorization.

121220205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26140.

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

The square root of 121220205 is about 11010.0047683913. The cubic root of 121220205 is about 494.9086046953.

Adding to 121220205 its reverse (502022121), we get a palindrome (623242326).

The spelling of 121220205 in words is "one hundred twenty-one million, two hundred twenty thousand, two hundred five".