129981893 has 2 divisors, whose sum is σ = 129981894. Its totient is φ = 129981892.

The previous prime is 129981877. The next prime is 129981899. The reversal of 129981893 is 398189921.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 117007489 + 12974404 = 10817^2 + 3602^2 .

It is an emirp because it is prime and its reverse (398189921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 129981893 - 2⁴ = 129981877 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129981899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64990946 + 64990947.

It is an arithmetic number, because the mean of its divisors is an integer number (64990947).

Almost surely, 2^129981893 is an apocalyptic number.

It is an amenable number.

129981893 is a deficient number, since it is larger than the sum of its proper divisors (1).

129981893 is an equidigital number, since it uses as much as digits as its factorization.

129981893 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 279936, while the sum is 50.

The square root of 129981893 is about 11400.9601788621. The cubic root of 129981893 is about 506.5561812317.

The spelling of 129981893 in words is "one hundred twenty-nine million, nine hundred eighty-one thousand, eight hundred ninety-three".