123171378013 has 4 divisors (see below), whose sum is σ = 127418666940. Its totient is φ = 118924089088.

The previous prime is 123171377977. The next prime is 123171378041. The reversal of 123171378013 is 310873171321.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30096351289 + 93075026724 = 173483^2 + 305082^2 .

It is a cyclic number.

It is not a de Polignac number, because 123171378013 - 2³³ = 114581443421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123171375013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2123644420 + ... + 2123644477.

It is an arithmetic number, because the mean of its divisors is an integer number (31854666735).

Almost surely, 2^123171378013 is an apocalyptic number.

It is an amenable number.

123171378013 is a deficient number, since it is larger than the sum of its proper divisors (4247288927).

123171378013 is an equidigital number, since it uses as much as digits as its factorization.

123171378013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4247288926.

The product of its (nonzero) digits is 21168, while the sum is 37.

The spelling of 123171378013 in words is "one hundred twenty-three billion, one hundred seventy-one million, three hundred seventy-eight thousand, thirteen".