129444921 has 24 divisors (see below), whose sum is σ = 194965056. Its totient is φ = 82686240.

The previous prime is 129444911. The next prime is 129444947.

129444921 is a `hidden beast` number, since 129 + 44 + 492 + 1 = 666.

129444921 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 129444921 - 2¹³ = 129436729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129444911) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17356 + ... + 23666.

It is an arithmetic number, because the mean of its divisors is an integer number (8123544).

Almost surely, 2^129444921 is an apocalyptic number.

It is an amenable number.

129444921 is a deficient number, since it is larger than the sum of its proper divisors (65520135).

129444921 is a wasteful number, since it uses less digits than its factorization.

129444921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6413 (or 6410 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 129444921 is about 11377.3863870399. The cubic root of 129444921 is about 505.8576687796.

The spelling of 129444921 in words is "one hundred twenty-nine million, four hundred forty-four thousand, nine hundred twenty-one".