121678861 has 2 divisors, whose sum is σ = 121678862. Its totient is φ = 121678860.

The previous prime is 121678859. The next prime is 121678871. The reversal of 121678861 is 168876121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79103236 + 42575625 = 8894^2 + 6525^2 .

It is a cyclic number.

It is not a de Polignac number, because 121678861 - 2¹ = 121678859 is a prime.

Together with 121678859, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121678871) 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 as a sum of consecutive naturals, namely, 60839430 + 60839431.

It is an arithmetic number, because the mean of its divisors is an integer number (60839431).

Almost surely, 2^121678861 is an apocalyptic number.

It is an amenable number.

121678861 is a deficient number, since it is larger than the sum of its proper divisors (1).

121678861 is an equidigital number, since it uses as much as digits as its factorization.

121678861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32256, while the sum is 40.

The square root of 121678861 is about 11030.8141585288. The cubic root of 121678861 is about 495.5320076817.

The spelling of 121678861 in words is "one hundred twenty-one million, six hundred seventy-eight thousand, eight hundred sixty-one".