129776531 has 2 divisors, whose sum is σ = 129776532. Its totient is φ = 129776530.

The previous prime is 129776513. The next prime is 129776533. The reversal of 129776531 is 135677921.

Together with previous prime (129776513) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 129776531 - 2²⁶ = 62667667 is a prime.

It is a super-2 number, since 2×129776531² = 33683895996787922, which contains 22 as substring.

Together with 129776533, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (129776533) 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, 64888265 + 64888266.

It is an arithmetic number, because the mean of its divisors is an integer number (64888266).

Almost surely, 2^129776531 is an apocalyptic number.

129776531 is a deficient number, since it is larger than the sum of its proper divisors (1).

129776531 is an equidigital number, since it uses as much as digits as its factorization.

129776531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 79380, while the sum is 41.

The square root of 129776531 is about 11391.9502720123. The cubic root of 129776531 is about 506.2892665575.

The spelling of 129776531 in words is "one hundred twenty-nine million, seven hundred seventy-six thousand, five hundred thirty-one".