123785861 has 2 divisors, whose sum is σ = 123785862. Its totient is φ = 123785860.

The previous prime is 123785843. The next prime is 123785887. The reversal of 123785861 is 168587321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 107536900 + 16248961 = 10370^2 + 4031^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123785861 is a prime.

It is a super-2 number, since 2×123785861² = 30645878767022642, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123785801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61892930 + 61892931.

It is an arithmetic number, because the mean of its divisors is an integer number (61892931).

Almost surely, 2^123785861 is an apocalyptic number.

It is an amenable number.

123785861 is a deficient number, since it is larger than the sum of its proper divisors (1).

123785861 is an equidigital number, since it uses as much as digits as its factorization.

123785861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 41.

The square root of 123785861 is about 11125.9094459734. The cubic root of 123785861 is about 498.3758781686.

It can be divided in two parts, 12 and 3785861, that added together give a palindrome (3785873).

The spelling of 123785861 in words is "one hundred twenty-three million, seven hundred eighty-five thousand, eight hundred sixty-one".