2039721 has 4 divisors (see below), whose sum is σ = 2719632. Its totient is φ = 1359812.

The previous prime is 2039671. The next prime is 2039731. The reversal of 2039721 is 1279302.

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.

It is a cyclic number.

It is not a de Polignac number, because 2039721 - 2¹⁴ = 2023337 is a prime.

It is a D-number.

2039721 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 2039691 and 2039700.

It is not an unprimeable number, because it can be changed into a prime (2039731) 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, 339951 + ... + 339956.

It is an arithmetic number, because the mean of its divisors is an integer number (679908).

2^2039721 is an apocalyptic number.

It is an amenable number.

2039721 is a deficient number, since it is larger than the sum of its proper divisors (679911).

2039721 is an equidigital number, since it uses as much as digits as its factorization.

2039721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679910.

The product of its (nonzero) digits is 756, while the sum is 24.

The square root of 2039721 is about 1428.1880128330. The cubic root of 2039721 is about 126.8207320471.

The spelling of 2039721 in words is "two million, thirty-nine thousand, seven hundred twenty-one".