129408681 has 4 divisors (see below), whose sum is σ = 172544912. Its totient is φ = 86272452.

The previous prime is 129408679. The next prime is 129408683. The reversal of 129408681 is 186804921.

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.

It is an interprime number because it is at equal distance from previous prime (129408679) and next prime (129408683).

It is not a de Polignac number, because 129408681 - 2¹ = 129408679 is a prime.

It is a super-2 number, since 2×129408681² = 33493213436319522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129408683) 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, 21568111 + ... + 21568116.

It is an arithmetic number, because the mean of its divisors is an integer number (43136228).

Almost surely, 2^129408681 is an apocalyptic number.

It is an amenable number.

129408681 is a deficient number, since it is larger than the sum of its proper divisors (43136231).

129408681 is an equidigital number, since it uses as much as digits as its factorization.

129408681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43136230.

The product of its (nonzero) digits is 27648, while the sum is 39.

The square root of 129408681 is about 11375.7936426431. The cubic root of 129408681 is about 505.8104569543.

The spelling of 129408681 in words is "one hundred twenty-nine million, four hundred eight thousand, six hundred eighty-one".