127392721 has 4 divisors (see below), whose sum is σ = 127417444. Its totient is φ = 127368000.

The previous prime is 127392709. The next prime is 127392757. The reversal of 127392721 is 127293721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127293721 = 9173 ⋅13877.

It can be written as a sum of positive squares in 2 ways, for example, as 23658496 + 103734225 = 4864^2 + 10185^2 .

It is a cyclic number.

It is not a de Polignac number, because 127392721 - 2⁷ = 127392593 is a prime.

It is a super-3 number, since 3×127392721³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (127392521) 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, 1380 + ... + 16021.

It is an arithmetic number, because the mean of its divisors is an integer number (31854361).

Almost surely, 2^127392721 is an apocalyptic number.

It is an amenable number.

127392721 is a deficient number, since it is larger than the sum of its proper divisors (24723).

127392721 is an equidigital number, since it uses as much as digits as its factorization.

127392721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24722.

The product of its digits is 10584, while the sum is 34.

The square root of 127392721 is about 11286.8383970003. The cubic root of 127392721 is about 503.1701524540.

The spelling of 127392721 in words is "one hundred twenty-seven million, three hundred ninety-two thousand, seven hundred twenty-one".