123170853781 has 2 divisors, whose sum is σ = 123170853782. Its totient is φ = 123170853780.

The previous prime is 123170853779. The next prime is 123170853787. The reversal of 123170853781 is 187358071321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66332002500 + 56838851281 = 257550^2 + 238409^2 .

It is a cyclic number.

It is not a de Polignac number, because 123170853781 - 2¹ = 123170853779 is a prime.

It is a super-2 number, since 2×123170853781² (a number of 23 digits) contains 22 as substring.

Together with 123170853779, 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 (123170853787) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61585426890 + 61585426891.

It is an arithmetic number, because the mean of its divisors is an integer number (61585426891).

Almost surely, 2^123170853781 is an apocalyptic number.

It is an amenable number.

123170853781 is a deficient number, since it is larger than the sum of its proper divisors (1).

123170853781 is an equidigital number, since it uses as much as digits as its factorization.

123170853781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 282240, while the sum is 46.

The spelling of 123170853781 in words is "one hundred twenty-three billion, one hundred seventy million, eight hundred fifty-three thousand, seven hundred eighty-one".