121778829187 has 2 divisors, whose sum is σ = 121778829188. Its totient is φ = 121778829186.

The previous prime is 121778829157. The next prime is 121778829209. The reversal of 121778829187 is 781928877121.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121778829187 is a prime.

It is not a weakly prime, because it can be changed into another prime (121778829157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60889414593 + 60889414594.

It is an arithmetic number, because the mean of its divisors is an integer number (60889414594).

Almost surely, 2^121778829187 is an apocalyptic number.

121778829187 is a deficient number, since it is larger than the sum of its proper divisors (1).

121778829187 is an equidigital number, since it uses as much as digits as its factorization.

121778829187 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6322176, while the sum is 61.

The spelling of 121778829187 in words is "one hundred twenty-one billion, seven hundred seventy-eight million, eight hundred twenty-nine thousand, one hundred eighty-seven".