121389918 has 32 divisors (see below), whose sum is σ = 262174752. Its totient is φ = 37248000.

The previous prime is 121389913. The next prime is 121389937. The reversal of 121389918 is 819983121.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 121389918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121389913) 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, 29338 + ... + 33218.

It is an arithmetic number, because the mean of its divisors is an integer number (8192961).

Almost surely, 2^121389918 is an apocalyptic number.

121389918 is an abundant number, since it is smaller than the sum of its proper divisors (140784834).

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

121389918 is a wasteful number, since it uses less digits than its factorization.

121389918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4300.

The product of its digits is 31104, while the sum is 42.

The square root of 121389918 is about 11017.7092900475. The cubic root of 121389918 is about 495.1394607558.

The spelling of 121389918 in words is "one hundred twenty-one million, three hundred eighty-nine thousand, nine hundred eighteen".