121220405 has 8 divisors (see below), whose sum is σ = 146219352. Its totient is φ = 96473088.

The previous prime is 121220401. The next prime is 121220413. The reversal of 121220405 is 504022121.

It can be written as a sum of positive squares in 4 ways, for example, as 703921 + 120516484 = 839^2 + 10978^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 121220405 - 2² = 121220401 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121220401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 61844 + ... + 63773.

It is an arithmetic number, because the mean of its divisors is an integer number (18277419).

Almost surely, 2^121220405 is an apocalyptic number.

It is an amenable number.

121220405 is a deficient number, since it is larger than the sum of its proper divisors (24998947).

121220405 is a wasteful number, since it uses less digits than its factorization.

121220405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125815.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 121220405 is about 11010.0138510358. The cubic root of 121220405 is about 494.9088768767.

Adding to 121220405 its reverse (504022121), we get a palindrome (625242526).

The spelling of 121220405 in words is "one hundred twenty-one million, two hundred twenty thousand, four hundred five".