129999256606 has 4 divisors (see below), whose sum is σ = 194998884912. Its totient is φ = 64999628302.

The previous prime is 129999256591. The next prime is 129999256609. The reversal of 129999256606 is 606652999921.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×129999256606² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129999256609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32499814150 + ... + 32499814153.

It is an arithmetic number, because the mean of its divisors is an integer number (48749721228).

Almost surely, 2^129999256606 is an apocalyptic number.

129999256606 is a deficient number, since it is larger than the sum of its proper divisors (64999628306).

129999256606 is an equidigital number, since it uses as much as digits as its factorization.

129999256606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64999628305.

The product of its (nonzero) digits is 28343520, while the sum is 64.

The spelling of 129999256606 in words is "one hundred twenty-nine billion, nine hundred ninety-nine million, two hundred fifty-six thousand, six hundred six".