129756929 has 4 divisors (see below), whose sum is σ = 132774576. Its totient is φ = 126739284.

The previous prime is 129756919. The next prime is 129756931. The reversal of 129756929 is 929657921.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 929657921 = 13577 ⋅68473.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129756929 is a prime.

It is a super-2 number, since 2×129756929² = 33673721247022082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129756919) 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 in 3 ways as a sum of consecutive naturals, for example, 1508759 + ... + 1508844.

It is an arithmetic number, because the mean of its divisors is an integer number (33193644).

Almost surely, 2^129756929 is an apocalyptic number.

It is an amenable number.

129756929 is a deficient number, since it is larger than the sum of its proper divisors (3017647).

129756929 is an equidigital number, since it uses as much as digits as its factorization.

129756929 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3017646.

The product of its digits is 612360, while the sum is 50.

The square root of 129756929 is about 11391.0898951768. The cubic root of 129756929 is about 506.2637745782.

The spelling of 129756929 in words is "one hundred twenty-nine million, seven hundred fifty-six thousand, nine hundred twenty-nine".