2939721 has 4 divisors (see below), whose sum is σ = 3919632. Its totient is φ = 1959812.

The previous prime is 2939707. The next prime is 2939747. The reversal of 2939721 is 1279392.

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 2939721 - 2⁵ = 2939689 is a prime.

It is a D-number.

2939721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2939821) 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, 489951 + ... + 489956.

It is an arithmetic number, because the mean of its divisors is an integer number (979908).

2^2939721 is an apocalyptic number.

It is an amenable number.

2939721 is a deficient number, since it is larger than the sum of its proper divisors (979911).

2939721 is an equidigital number, since it uses as much as digits as its factorization.

2939721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 979910.

The product of its digits is 6804, while the sum is 33.

The square root of 2939721 is about 1714.5614599658. The cubic root of 2939721 is about 143.2524433916.

The spelling of 2939721 in words is "two million, nine hundred thirty-nine thousand, seven hundred twenty-one".