2999721 has 4 divisors (see below), whose sum is σ = 3999632. Its totient is φ = 1999812.

The previous prime is 2999707. The next prime is 2999767. The reversal of 2999721 is 1279992.

It is a happy number.

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 not a de Polignac number, because 2999721 - 2¹⁹ = 2475433 is a prime.

It is a D-number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2999721.

It is not an unprimeable number, because it can be changed into a prime (2999921) 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, 499951 + ... + 499956.

It is an arithmetic number, because the mean of its divisors is an integer number (999908).

2^2999721 is an apocalyptic number.

It is an amenable number.

2999721 is a deficient number, since it is larger than the sum of its proper divisors (999911).

2999721 is an equidigital number, since it uses as much as digits as its factorization.

2999721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 999910.

The product of its digits is 20412, while the sum is 39.

The square root of 2999721 is about 1731.9702653337. The cubic root of 2999721 is about 144.2204859185.

The spelling of 2999721 in words is "two million, nine hundred ninety-nine thousand, seven hundred twenty-one".