1339721 has 4 divisors (see below), whose sum is σ = 1352832. Its totient is φ = 1326612.

The previous prime is 1339711. The next prime is 1339729. The reversal of 1339721 is 1279331.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1279331 = 613 ⋅2087.

It is a cyclic number.

It is not a de Polignac number, because 1339721 - 2¹⁴ = 1323337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1339729) 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, 6401 + ... + 6606.

It is an arithmetic number, because the mean of its divisors is an integer number (338208).

2^1339721 is an apocalyptic number.

It is an amenable number.

1339721 is a deficient number, since it is larger than the sum of its proper divisors (13111).

1339721 is a wasteful number, since it uses less digits than its factorization.

1339721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13110.

The product of its digits is 1134, while the sum is 26.

The square root of 1339721 is about 1157.4631743602. The cubic root of 1339721 is about 110.2397251168.

The spelling of 1339721 in words is "one million, three hundred thirty-nine thousand, seven hundred twenty-one".