178255853981 has 2 divisors, whose sum is σ = 178255853982. Its totient is φ = 178255853980.

The previous prime is 178255853917. The next prime is 178255853987. The reversal of 178255853981 is 189358552871.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 136800857956 + 41454996025 = 369866^2 + 203605^2 .

It is an emirp because it is prime and its reverse (189358552871) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 178255853981 - 2⁶ = 178255853917 is a prime.

It is a super-2 number, since 2×178255853981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (178255853987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 89127926990 + 89127926991.

It is an arithmetic number, because the mean of its divisors is an integer number (89127926991).

Almost surely, 2^178255853981 is an apocalyptic number.

It is an amenable number.

178255853981 is a deficient number, since it is larger than the sum of its proper divisors (1).

178255853981 is an equidigital number, since it uses as much as digits as its factorization.

178255853981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192000, while the sum is 62.

The spelling of 178255853981 in words is "one hundred seventy-eight billion, two hundred fifty-five million, eight hundred fifty-three thousand, nine hundred eighty-one".