2667721 has 4 divisors (see below), whose sum is σ = 3048832. Its totient is φ = 2286612.

The previous prime is 2667689. The next prime is 2667727. The reversal of 2667721 is 1277662.

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 2667721 - 2⁵ = 2667689 is a prime.

It is a d-powerful number, because it can be written as 2⁷ + 6⁶ + 6⁸ + 7⁶ + 7⁷ + 2⁷ + 1 .

It is a Duffinian number.

2667721 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2667727) 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, 190545 + ... + 190558.

It is an arithmetic number, because the mean of its divisors is an integer number (762208).

2^2667721 is an apocalyptic number.

It is an amenable number.

2667721 is a deficient number, since it is larger than the sum of its proper divisors (381111).

2667721 is an equidigital number, since it uses as much as digits as its factorization.

2667721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381110.

The product of its digits is 7056, while the sum is 31.

The square root of 2667721 is about 1633.3159522885. The cubic root of 2667721 is about 138.6905283096.

The spelling of 2667721 in words is "two million, six hundred sixty-seven thousand, seven hundred twenty-one".