12121989 has 16 divisors (see below), whose sum is σ = 18399744. Its totient is φ = 7026800.

The previous prime is 12121987. The next prime is 12122009. The reversal of 12121989 is 98912121.

It is not a de Polignac number, because 12121989 - 2¹ = 12121987 is a prime.

It is a super-2 number, since 2×12121989² = 293885234632242, which contains 22 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121987) 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, 7227 + ... + 8744.

It is an arithmetic number, because the mean of its divisors is an integer number (1149984).

Almost surely, 2^12121989 is an apocalyptic number.

It is an amenable number.

12121989 is a deficient number, since it is larger than the sum of its proper divisors (6277755).

12121989 is a wasteful number, since it uses less digits than its factorization.

12121989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16008.

The product of its digits is 2592, while the sum is 33.

The square root of 12121989 is about 3481.6646880479. The cubic root of 12121989 is about 229.7160263427.

The spelling of 12121989 in words is "twelve million, one hundred twenty-one thousand, nine hundred eighty-nine".