1272721 has 4 divisors (see below), whose sum is σ = 1278244. Its totient is φ = 1267200.

The previous prime is 1272679. The next prime is 1272749.

1272721 is nontrivially palindromic in base 10.

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 541696 + 731025 = 736^2 + 855^2 .

It is a cyclic number.

It is not a de Polignac number, because 1272721 - 2¹⁷ = 1141649 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1272692 and 1272701.

It is not an unprimeable number, because it can be changed into a prime (1272421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2400 + ... + 2881.

It is an arithmetic number, because the mean of its divisors is an integer number (319561).

2^1272721 is an apocalyptic number.

It is an amenable number.

1272721 is a deficient number, since it is larger than the sum of its proper divisors (5523).

1272721 is an equidigital number, since it uses as much as digits as its factorization.

1272721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5522.

The product of its digits is 392, while the sum is 22.

The square root of 1272721 is about 1128.1493695429. The cubic root of 1272721 is about 108.3704982284.

The spelling of 1272721 in words is "one million, two hundred seventy-two thousand, seven hundred twenty-one".