127938721 has 3 divisors (see below), whose sum is σ = 127950033. Its totient is φ = 127927410.

The previous prime is 127938709. The next prime is 127938739. The reversal of 127938721 is 127839721.

It is a happy number.

The square root of 127938721 is 11311.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 127839721 = 8513 ⋅15017.

It is not a de Polignac number, because 127938721 - 2⁵ = 127938689 is a prime.

It is a super-2 number, since 2×127938721² = 32736632662231682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (127938751) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 5656 + ... + 16966.

It is an arithmetic number, because the mean of its divisors is an integer number (42650011).

Almost surely, 2^127938721 is an apocalyptic number.

127938721 is the 11311-st square number.

127938721 is the 5656-th centered octagonal number.

It is an amenable number.

127938721 is a deficient number, since it is larger than the sum of its proper divisors (11312).

127938721 is an frugal number, since it uses more digits than its factorization.

127938721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22622 (or 11311 counting only the distinct ones).

The product of its digits is 42336, while the sum is 40.

The cubic root of 127938721 is about 503.8879834725.

It can be divided in two parts, 1279 and 38721, that added together give a square (40000 = 200²).

The spelling of 127938721 in words is "one hundred twenty-seven million, nine hundred thirty-eight thousand, seven hundred twenty-one".