129091531 has 2 divisors, whose sum is σ = 129091532. Its totient is φ = 129091530.

The previous prime is 129091511. The next prime is 129091549. The reversal of 129091531 is 135190921.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129091531 is a prime.

It is a super-2 number, since 2×129091531² = 33329246751847922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 129091493 and 129091502.

It is not a weakly prime, because it can be changed into another prime (129091511) 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, 64545765 + 64545766.

It is an arithmetic number, because the mean of its divisors is an integer number (64545766).

Almost surely, 2^129091531 is an apocalyptic number.

129091531 is a deficient number, since it is larger than the sum of its proper divisors (1).

129091531 is an equidigital number, since it uses as much as digits as its factorization.

129091531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2430, while the sum is 31.

The square root of 129091531 is about 11361.8454046867. The cubic root of 129091531 is about 505.3969117615.

The spelling of 129091531 in words is "one hundred twenty-nine million, ninety-one thousand, five hundred thirty-one".