129677856 has 192 divisors, whose sum is σ = 433714176. Its totient is φ = 32947200.

The previous prime is 129677851. The next prime is 129677861. The reversal of 129677856 is 658776921.

It is an interprime number because it is at equal distance from previous prime (129677851) and next prime (129677861).

It is a junction number, because it is equal to n+sod(n) for n = 129677799 and 129677808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129677851) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 391611 + ... + 391941.

It is an arithmetic number, because the mean of its divisors is an integer number (2258928).

Almost surely, 2^129677856 is an apocalyptic number.

129677856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129677856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (216857088).

129677856 is an abundant number, since it is smaller than the sum of its proper divisors (304036320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129677856 is a wasteful number, since it uses less digits than its factorization.

129677856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 415 (or 407 counting only the distinct ones).

The product of its digits is 1270080, while the sum is 51.

The square root of 129677856 is about 11387.6185394489. The cubic root of 129677856 is about 506.1609157682.

The spelling of 129677856 in words is "one hundred twenty-nine million, six hundred seventy-seven thousand, eight hundred fifty-six".