12423781 has 2 divisors, whose sum is σ = 12423782. Its totient is φ = 12423780.

The previous prime is 12423767. The next prime is 12423799. The reversal of 12423781 is 18732421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6806881 + 5616900 = 2609^2 + 2370^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12423781 is a prime.

It is a super-2 number, since 2×12423781² = 308700668671922, which contains 22 as substring.

It is equal to p₈₁₄₀₇₈ and since 12423781 and 814078 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12423731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6211890 + 6211891.

It is an arithmetic number, because the mean of its divisors is an integer number (6211891).

Almost surely, 2^12423781 is an apocalyptic number.

It is an amenable number.

12423781 is a deficient number, since it is larger than the sum of its proper divisors (1).

12423781 is an equidigital number, since it uses as much as digits as its factorization.

12423781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2688, while the sum is 28.

The square root of 12423781 is about 3524.7384300115. The cubic root of 12423781 is about 231.6067766677.

The spelling of 12423781 in words is "twelve million, four hundred twenty-three thousand, seven hundred eighty-one".