2851721 has 8 divisors (see below), whose sum is σ = 2989824. Its totient is φ = 2716560.

The previous prime is 2851661. The next prime is 2851727. The reversal of 2851721 is 1271582.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2851721 - 2¹⁰ = 2850697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2851727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1391 + ... + 2763.

It is an arithmetic number, because the mean of its divisors is an integer number (373728).

2^2851721 is an apocalyptic number.

It is an amenable number.

2851721 is a deficient number, since it is larger than the sum of its proper divisors (138103).

2851721 is a wasteful number, since it uses less digits than its factorization.

2851721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1471.

The product of its digits is 1120, while the sum is 26.

The square root of 2851721 is about 1688.7039408967. The cubic root of 2851721 is about 141.8085265651.

The spelling of 2851721 in words is "two million, eight hundred fifty-one thousand, seven hundred twenty-one".