2665521 has 16 divisors (see below), whose sum is σ = 3974400. Its totient is φ = 1765584.

The previous prime is 2665513. The next prime is 2665547. The reversal of 2665521 is 1255662.

2665521 is a `hidden beast` number, since 2 + 6 + 655 + 2 + 1 = 666.

It is not a de Polignac number, because 2665521 - 2³ = 2665513 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an Ulam number.

It is a Curzon number.

2665521 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2665501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7080 + ... + 7446.

It is an arithmetic number, because the mean of its divisors is an integer number (248400).

2^2665521 is an apocalyptic number.

It is an amenable number.

2665521 is a deficient number, since it is larger than the sum of its proper divisors (1308879).

2665521 is a wasteful number, since it uses less digits than its factorization.

2665521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645 (or 639 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 2665521 is about 1632.6423368270. The cubic root of 2665521 is about 138.6523930030.

The spelling of 2665521 in words is "two million, six hundred sixty-five thousand, five hundred twenty-one".