121639181 has 2 divisors, whose sum is σ = 121639182. Its totient is φ = 121639180.

The previous prime is 121639153. The next prime is 121639183. The reversal of 121639181 is 181936121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87123556 + 34515625 = 9334^2 + 5875^2 .

It is a cyclic number.

It is not a de Polignac number, because 121639181 - 2¹⁰ = 121638157 is a prime.

It is a super-2 number, since 2×121639181² = 29592180708701522, which contains 22 as substring.

Together with 121639183, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121639183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60819590 + 60819591.

It is an arithmetic number, because the mean of its divisors is an integer number (60819591).

Almost surely, 2^121639181 is an apocalyptic number.

It is an amenable number.

121639181 is a deficient number, since it is larger than the sum of its proper divisors (1).

121639181 is an equidigital number, since it uses as much as digits as its factorization.

121639181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2592, while the sum is 32.

The square root of 121639181 is about 11029.0154138980. The cubic root of 121639181 is about 495.4781367857.

The spelling of 121639181 in words is "one hundred twenty-one million, six hundred thirty-nine thousand, one hundred eighty-one".