129811768 has 8 divisors (see below), whose sum is σ = 243397080. Its totient is φ = 64905880.

The previous prime is 129811757. The next prime is 129811769. The reversal of 129811768 is 867118921.

It is a happy number.

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

It is a super-2 number, since 2×129811768² = 33702190222571648, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129811769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8113228 + ... + 8113243.

It is an arithmetic number, because the mean of its divisors is an integer number (30424635).

Almost surely, 2^129811768 is an apocalyptic number.

It is an amenable number.

129811768 is a deficient number, since it is larger than the sum of its proper divisors (113585312).

129811768 is a wasteful number, since it uses less digits than its factorization.

129811768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16226477 (or 16226473 counting only the distinct ones).

The product of its digits is 48384, while the sum is 43.

The square root of 129811768 is about 11393.4967415627. The cubic root of 129811768 is about 506.3350850639.

The spelling of 129811768 in words is "one hundred twenty-nine million, eight hundred eleven thousand, seven hundred sixty-eight".