121800405 has 8 divisors (see below), whose sum is σ = 194880672. Its totient is φ = 64960208.

The previous prime is 121800397. The next prime is 121800409. The reversal of 121800405 is 504008121.

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 121800405 - 2³ = 121800397 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121800409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4059999 + ... + 4060028.

It is an arithmetic number, because the mean of its divisors is an integer number (24360084).

Almost surely, 2^121800405 is an apocalyptic number.

121800405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121800405 is a deficient number, since it is larger than the sum of its proper divisors (73080267).

121800405 is an equidigital number, since it uses as much as digits as its factorization.

121800405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8120035.

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 121800405 is about 11036.3220775764. The cubic root of 121800405 is about 495.6969470391.

Adding to 121800405 its reverse (504008121), we get a palindrome (625808526).

The spelling of 121800405 in words is "one hundred twenty-one million, eight hundred thousand, four hundred five".