123855781 has 24 divisors (see below), whose sum is σ = 152586720. Its totient is φ = 100068192.

The previous prime is 123855709. The next prime is 123855821. The reversal of 123855781 is 187558321.

It is not a de Polignac number, because 123855781 - 2¹¹ = 123853733 is a prime.

It is a super-2 number, since 2×123855781² = 30680508974239922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123855581) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60090 + ... + 62116.

It is an arithmetic number, because the mean of its divisors is an integer number (6357780).

Almost surely, 2^123855781 is an apocalyptic number.

It is an amenable number.

123855781 is a deficient number, since it is larger than the sum of its proper divisors (28730939).

123855781 is a wasteful number, since it uses less digits than its factorization.

123855781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2113 (or 2106 counting only the distinct ones).

The product of its digits is 67200, while the sum is 40.

The square root of 123855781 is about 11129.0512174219. The cubic root of 123855781 is about 498.4696957830.

The spelling of 123855781 in words is "one hundred twenty-three million, eight hundred fifty-five thousand, seven hundred eighty-one".