12008005781 has 2 divisors, whose sum is σ = 12008005782. Its totient is φ = 12008005780.

The previous prime is 12008005729. The next prime is 12008005813. The reversal of 12008005781 is 18750080021.

It is a happy number.

It is an a-pointer prime, because the next prime (12008005813) can be obtained adding 12008005781 to its sum of digits (32).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11912631025 + 95374756 = 109145^2 + 9766^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12008005781 is a prime.

It is a super-2 number, since 2×12008005781² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12008004781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6004002890 + 6004002891.

It is an arithmetic number, because the mean of its divisors is an integer number (6004002891).

Almost surely, 2^12008005781 is an apocalyptic number.

It is an amenable number.

12008005781 is a deficient number, since it is larger than the sum of its proper divisors (1).

12008005781 is an equidigital number, since it uses as much as digits as its factorization.

12008005781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4480, while the sum is 32.

The spelling of 12008005781 in words is "twelve billion, eight million, five thousand, seven hundred eighty-one".