123956851839 has 4 divisors (see below), whose sum is σ = 165275802456. Its totient is φ = 82637901224.

The previous prime is 123956851807. The next prime is 123956851853. The reversal of 123956851839 is 938158659321.

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

It is a cyclic number.

It is not a de Polignac number, because 123956851839 - 2⁵ = 123956851807 is a prime.

It is a super-2 number, since 2×123956851839² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123956851859) 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, 20659475304 + ... + 20659475309.

It is an arithmetic number, because the mean of its divisors is an integer number (41318950614).

Almost surely, 2^123956851839 is an apocalyptic number.

123956851839 is a deficient number, since it is larger than the sum of its proper divisors (41318950617).

123956851839 is an equidigital number, since it uses as much as digits as its factorization.

123956851839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41318950616.

The product of its digits is 13996800, while the sum is 60.

The spelling of 123956851839 in words is "one hundred twenty-three billion, nine hundred fifty-six million, eight hundred fifty-one thousand, eight hundred thirty-nine".