2016721 has 8 divisors (see below), whose sum is σ = 2343104. Its totient is φ = 1699920.

The previous prime is 2016697. The next prime is 2016733. The reversal of 2016721 is 1276102.

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 2016721 - 2⁷ = 2016593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2016821) 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, 1935 + ... + 2788.

It is an arithmetic number, because the mean of its divisors is an integer number (292888).

2^2016721 is an apocalyptic number.

It is an amenable number.

2016721 is a deficient number, since it is larger than the sum of its proper divisors (326383).

2016721 is an equidigital number, since it uses as much as digits as its factorization.

2016721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4791.

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 2016721 is about 1420.1130236710. The cubic root of 2016721 is about 126.3422499970.

The spelling of 2016721 in words is "two million, sixteen thousand, seven hundred twenty-one".