129781447 has 2 divisors, whose sum is σ = 129781448. Its totient is φ = 129781446.

The previous prime is 129781403. The next prime is 129781453. The reversal of 129781447 is 744187921.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 129781447 - 2⁷ = 129781319 is a prime.

It is a super-3 number, since 3×129781447³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129787447) 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 as a sum of consecutive naturals, namely, 64890723 + 64890724.

It is an arithmetic number, because the mean of its divisors is an integer number (64890724).

Almost surely, 2^129781447 is an apocalyptic number.

129781447 is a deficient number, since it is larger than the sum of its proper divisors (1).

129781447 is an equidigital number, since it uses as much as digits as its factorization.

129781447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112896, while the sum is 43.

The square root of 129781447 is about 11392.1660363602. The cubic root of 129781447 is about 506.2956593071.

The spelling of 129781447 in words is "one hundred twenty-nine million, seven hundred eighty-one thousand, four hundred forty-seven".