129699996921 has 72 divisors (see below), whose sum is σ = 207338913600. Its totient is φ = 78068232000.

The previous prime is 129699996889. The next prime is 129699996967.

129699996921 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 129699996921 - 2⁵ = 129699996889 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 129699996921.

It is not an unprimeable number, because it can be changed into a prime (129699996721) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 125799676 + ... + 125800706.

Almost surely, 2^129699996921 is an apocalyptic number.

129699996921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

129699996921 is a deficient number, since it is larger than the sum of its proper divisors (77638916679).

129699996921 is a wasteful number, since it uses less digits than its factorization.

129699996921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1739 (or 1725 counting only the distinct ones).

The product of its digits is 76527504, while the sum is 72.

The spelling of 129699996921 in words is "one hundred twenty-nine billion, six hundred ninety-nine million, nine hundred ninety-six thousand, nine hundred twenty-one".