2128129727 has 4 divisors (see below), whose sum is σ = 2177621160. Its totient is φ = 2078638296.

The previous prime is 2128129709. The next prime is 2128129739. The reversal of 2128129727 is 7279218212.

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 2128129727 - 2¹² = 2128125631 is a prime.

It is a super-2 number, since 2×2128129727² = 9057872269882189058, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2128129427) 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, 24745652 + ... + 24745737.

It is an arithmetic number, because the mean of its divisors is an integer number (544405290).

Almost surely, 2^2128129727 is an apocalyptic number.

2128129727 is a deficient number, since it is larger than the sum of its proper divisors (49491433).

2128129727 is an equidigital number, since it uses as much as digits as its factorization.

2128129727 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49491432.

The product of its digits is 56448, while the sum is 41.

The square root of 2128129727 is about 46131.6564519420. The cubic root of 2128129727 is about 1286.2716550838.

The spelling of 2128129727 in words is "two billion, one hundred twenty-eight million, one hundred twenty-nine thousand, seven hundred twenty-seven".