121212405 has 12 divisors (see below), whose sum is σ = 210101580. Its totient is φ = 64646592.

The previous prime is 121212391. The next prime is 121212439. The reversal of 121212405 is 504212121.

It can be written as a sum of positive squares in 2 ways, for example, as 18818244 + 102394161 = 4338^2 + 10119^2 .

It is not a de Polignac number, because 121212405 - 2⁶ = 121212341 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1346760 + ... + 1346849.

It is an arithmetic number, because the mean of its divisors is an integer number (17508465).

Almost surely, 2^121212405 is an apocalyptic number.

121212405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121212405 is a deficient number, since it is larger than the sum of its proper divisors (88889175).

121212405 is a wasteful number, since it uses less digits than its factorization.

121212405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2693620 (or 2693617 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 121212405 is about 11009.6505394131. The cubic root of 121212405 is about 494.8979893860.

Adding to 121212405 its reverse (504212121), we get a palindrome (625424526).

The spelling of 121212405 in words is "one hundred twenty-one million, two hundred twelve thousand, four hundred five".