123841981 has 4 divisors (see below), whose sum is σ = 130360000. Its totient is φ = 117323964.

The previous prime is 123841909. The next prime is 123841999. The reversal of 123841981 is 189148321.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123841981 is a prime.

It is a super-2 number, since 2×123841981² = 30673672516008722, which 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 123841981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123841681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3258981 + ... + 3259018.

It is an arithmetic number, because the mean of its divisors is an integer number (32590000).

Almost surely, 2^123841981 is an apocalyptic number.

It is an amenable number.

123841981 is a deficient number, since it is larger than the sum of its proper divisors (6518019).

123841981 is an equidigital number, since it uses as much as digits as its factorization.

123841981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6518018.

The product of its digits is 13824, while the sum is 37.

The square root of 123841981 is about 11128.4312012071. The cubic root of 123841981 is about 498.4511819458.

It can be divided in two parts, 12384 and 1981, that added together give a triangular number (14365 = T₁₆₉).

The spelling of 123841981 in words is "one hundred twenty-three million, eight hundred forty-one thousand, nine hundred eighty-one".