1231421855177 has 2 divisors, whose sum is σ = 1231421855178. Its totient is φ = 1231421855176.

The previous prime is 1231421855159. The next prime is 1231421855233. The reversal of 1231421855177 is 7715581241321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1092319709881 + 139102145296 = 1045141^2 + 372964^2 .

It is an emirp because it is prime and its reverse (7715581241321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1231421855177 - 2⁸ = 1231421854921 is a prime.

It is not a weakly prime, because it can be changed into another prime (1231421855137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615710927588 + 615710927589.

It is an arithmetic number, because the mean of its divisors is an integer number (615710927589).

Almost surely, 2^{1231421855177} is an apocalyptic number.

It is an amenable number.

1231421855177 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231421855177 is an equidigital number, since it uses as much as digits as its factorization.

1231421855177 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 470400, while the sum is 47.

The spelling of 1231421855177 in words is "one trillion, two hundred thirty-one billion, four hundred twenty-one million, eight hundred fifty-five thousand, one hundred seventy-seven".