129947749921 has 32 divisors (see below), whose sum is σ = 152583782400. Its totient is φ = 109401454080.

The previous prime is 129947749901. The next prime is 129947749937.

It is a happy number.

129947749921 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 129947749921 - 2⁵ = 129947749889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129947749901) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8469585 + ... + 8484913.

It is an arithmetic number, because the mean of its divisors is an integer number (4768243200).

Almost surely, 2^129947749921 is an apocalyptic number.

129947749921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

129947749921 is a deficient number, since it is larger than the sum of its proper divisors (22636032479).

129947749921 is a wasteful number, since it uses less digits than its factorization.

129947749921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16269.

The product of its digits is 20575296, while the sum is 64.

The spelling of 129947749921 in words is "one hundred twenty-nine billion, nine hundred forty-seven million, seven hundred forty-nine thousand, nine hundred twenty-one".