129403681 has 8 divisors (see below), whose sum is σ = 147305664. Its totient is φ = 112524720.

The previous prime is 129403649. The next prime is 129403691. The reversal of 129403681 is 186304921.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 129403681 - 2⁵ = 129403649 is a prime.

It is a super-2 number, since 2×129403681² = 33490625312699522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (129403691) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 255486 + ... + 255991.

It is an arithmetic number, because the mean of its divisors is an integer number (18413208).

Almost surely, 2^129403681 is an apocalyptic number.

129403681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

129403681 is the 6081-st centered heptagonal number.

It is an amenable number.

129403681 is a deficient number, since it is larger than the sum of its proper divisors (17901983).

129403681 is a wasteful number, since it uses less digits than its factorization.

129403681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511511.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 129403681 is about 11375.5738756337. The cubic root of 129403681 is about 505.8039424896.

The spelling of 129403681 in words is "one hundred twenty-nine million, four hundred three thousand, six hundred eighty-one".