129642271 has 4 divisors (see below), whose sum is σ = 141427944. Its totient is φ = 117856600.

The previous prime is 129642269. The next prime is 129642277. The reversal of 129642271 is 172246921.

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

It is a cyclic number.

It is not a de Polignac number, because 129642271 - 2¹ = 129642269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129642277) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5892820 + ... + 5892841.

It is an arithmetic number, because the mean of its divisors is an integer number (35356986).

Almost surely, 2^129642271 is an apocalyptic number.

129642271 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

129642271 is a deficient number, since it is larger than the sum of its proper divisors (11785673).

129642271 is a wasteful number, since it uses less digits than its factorization.

129642271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11785672.

The product of its digits is 12096, while the sum is 34.

The square root of 129642271 is about 11386.0559896744. The cubic root of 129642271 is about 506.1146128642.

The spelling of 129642271 in words is "one hundred twenty-nine million, six hundred forty-two thousand, two hundred seventy-one".