121989137 has 4 divisors (see below), whose sum is σ = 122020416. Its totient is φ = 121957860.

The previous prime is 121989121. The next prime is 121989143. The reversal of 121989137 is 731989121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 121989137 - 2⁴ = 121989121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121989094 and 121989103.

It is not an unprimeable number, because it can be changed into a prime (121989107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8789 + ... + 17922.

It is an arithmetic number, because the mean of its divisors is an integer number (30505104).

Almost surely, 2^121989137 is an apocalyptic number.

It is an amenable number.

121989137 is a deficient number, since it is larger than the sum of its proper divisors (31279).

121989137 is an equidigital number, since it uses as much as digits as its factorization.

121989137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31278.

The product of its digits is 27216, while the sum is 41.

The square root of 121989137 is about 11044.8692613358. The cubic root of 121989137 is about 495.9528454673.

The spelling of 121989137 in words is "one hundred twenty-one million, nine hundred eighty-nine thousand, one hundred thirty-seven".