129929281 has 4 divisors (see below), whose sum is σ = 131868592. Its totient is φ = 127989972.

The previous prime is 129929263. The next prime is 129929297. The reversal of 129929281 is 182929921.

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: 182929921 = 727 ⋅251623.

It is a cyclic number.

It is not a de Polignac number, because 129929281 - 2¹⁵ = 129896513 is a prime.

It is a super-2 number, since 2×129929281² = 33763236122353922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129929881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 969555 + ... + 969688.

It is an arithmetic number, because the mean of its divisors is an integer number (32967148).

Almost surely, 2^129929281 is an apocalyptic number.

It is an amenable number.

129929281 is a deficient number, since it is larger than the sum of its proper divisors (1939311).

129929281 is an equidigital number, since it uses as much as digits as its factorization.

129929281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1939310.

The product of its digits is 46656, while the sum is 43.

The square root of 129929281 is about 11398.6525958115. The cubic root of 129929281 is about 506.4878267613.

The spelling of 129929281 in words is "one hundred twenty-nine million, nine hundred twenty-nine thousand, two hundred eighty-one".