129312056 has 8 divisors (see below), whose sum is σ = 242460120. Its totient is φ = 64656024.

The previous prime is 129312037. The next prime is 129312059. The reversal of 129312056 is 650213921.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129312059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8081996 + ... + 8082011.

It is an arithmetic number, because the mean of its divisors is an integer number (30307515).

Almost surely, 2^129312056 is an apocalyptic number.

It is an amenable number.

129312056 is a deficient number, since it is larger than the sum of its proper divisors (113148064).

129312056 is a wasteful number, since it uses less digits than its factorization.

129312056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16164013 (or 16164009 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 129312056 is about 11371.5458931493. The cubic root of 129312056 is about 505.6845351995.

Adding to 129312056 its reverse (650213921), we get a palindrome (779525977).

The spelling of 129312056 in words is "one hundred twenty-nine million, three hundred twelve thousand, fifty-six".