121680289 has 4 divisors (see below), whose sum is σ = 122202756. Its totient is φ = 121157824.

The previous prime is 121680287. The next prime is 121680319. The reversal of 121680289 is 982086121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 982086121 = 3221 ⋅304901.

It can be written as a sum of positive squares in 2 ways, for example, as 9150625 + 112529664 = 3025^2 + 10608^2 .

It is a cyclic number.

It is not a de Polignac number, because 121680289 - 2¹ = 121680287 is a prime.

It is a super-2 number, since 2×121680289² = 29612185462247042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121680287) 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, 260884 + ... + 261349.

It is an arithmetic number, because the mean of its divisors is an integer number (30550689).

Almost surely, 2^121680289 is an apocalyptic number.

It is an amenable number.

121680289 is a deficient number, since it is larger than the sum of its proper divisors (522467).

121680289 is an equidigital number, since it uses as much as digits as its factorization.

121680289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522466.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 121680289 is about 11030.8788861088. The cubic root of 121680289 is about 495.5339461640.

The spelling of 121680289 in words is "one hundred twenty-one million, six hundred eighty thousand, two hundred eighty-nine".