127021 has 4 divisors (see below), whose sum is σ = 130492. Its totient is φ = 123552.

The previous prime is 126989. The next prime is 127031. The reversal of 127021 is 120721.

It is the 146-th star number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 81225 + 45796 = 285^2 + 214^2 .

It is a cyclic number.

It is not a de Polignac number, because 127021 - 2⁵ = 126989 is a prime.

It is a super-2 number, since 2×127021² = 32268668882, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 126992 and 127010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (127031) 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, 1680 + ... + 1753.

It is an arithmetic number, because the mean of its divisors is an integer number (32623).

2¹²⁷⁰²¹ is an apocalyptic number.

It is an amenable number.

127021 is a deficient number, since it is larger than the sum of its proper divisors (3471).

127021 is an equidigital number, since it uses as much as digits as its factorization.

127021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3470.

The product of its (nonzero) digits is 28, while the sum is 13.

The square root of 127021 is about 356.4000561167. The cubic root of 127021 is about 50.2680273264.

Adding to 127021 its reverse (120721), we get a palindrome (247742).

The spelling of 127021 in words is "one hundred twenty-seven thousand, twenty-one", and thus it is an iban number.