123285891731 has 4 divisors (see below), whose sum is σ = 124256646912. Its totient is φ = 122315136552.

The previous prime is 123285891697. The next prime is 123285891733. The reversal of 123285891731 is 137198582321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 137198582321 = 1523 ⋅90084427.

It is a cyclic number.

It is not a de Polignac number, because 123285891731 - 2⁶ = 123285891667 is a prime.

It is a super-2 number, since 2×123285891731² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 123285891731.

It is not an unprimeable number, because it can be changed into a prime (123285891733) 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 in 3 ways as a sum of consecutive naturals, for example, 485377400 + ... + 485377653.

It is an arithmetic number, because the mean of its divisors is an integer number (31064161728).

Almost surely, 2^123285891731 is an apocalyptic number.

123285891731 is a deficient number, since it is larger than the sum of its proper divisors (970755181).

123285891731 is an equidigital number, since it uses as much as digits as its factorization.

123285891731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 970755180.

The product of its digits is 725760, while the sum is 50.

The spelling of 123285891731 in words is "one hundred twenty-three billion, two hundred eighty-five million, eight hundred ninety-one thousand, seven hundred thirty-one".