2663721 has 12 divisors (see below), whose sum is σ = 3937648. Its totient is φ = 1734264.

The previous prime is 2663711. The next prime is 2663761. The reversal of 2663721 is 1273662.

It is a happy number.

2663721 is a `hidden beast` number, since 2 + 6 + 637 + 21 = 666.

It is not a de Polignac number, because 2663721 - 2⁹ = 2663209 is a prime.

It is a d-powerful number, because it can be written as 2⁷ + 6⁷ + 6⁷ + 3⁸ + 7 + 2²¹ + 1 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2663701) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3055 + ... + 3828.

2^2663721 is an apocalyptic number.

It is an amenable number.

2663721 is a deficient number, since it is larger than the sum of its proper divisors (1273927).

2663721 is a wasteful number, since it uses less digits than its factorization.

2663721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6932 (or 6929 counting only the distinct ones).

The product of its digits is 3024, while the sum is 27.

The square root of 2663721 is about 1632.0909901105. The cubic root of 2663721 is about 138.6211757779.

The spelling of 2663721 in words is "two million, six hundred sixty-three thousand, seven hundred twenty-one".