129905506 has 8 divisors (see below), whose sum is σ = 196392960. Its totient is φ = 64441188.

The previous prime is 129905497. The next prime is 129905513. The reversal of 129905506 is 605509921.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 255466 + ... + 255973.

It is an arithmetic number, because the mean of its divisors is an integer number (24549120).

Almost surely, 2^129905506 is an apocalyptic number.

129905506 is a deficient number, since it is larger than the sum of its proper divisors (66487454).

129905506 is a wasteful number, since it uses less digits than its factorization.

129905506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511568.

The product of its (nonzero) digits is 24300, while the sum is 37.

The square root of 129905506 is about 11397.6096616791. The cubic root of 129905506 is about 506.4569317940.

It can be divided in two parts, 12990 and 5506, that added together give a square (18496 = 136²).

The spelling of 129905506 in words is "one hundred twenty-nine million, nine hundred five thousand, five hundred six".