2655621 has 18 divisors (see below), whose sum is σ = 4078802. Its totient is φ = 1664640.

The previous prime is 2655607. The next prime is 2655623. The reversal of 2655621 is 1265562.

2655621 is a `hidden beast` number, since 2 + 655 + 6 + 2 + 1 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 1179396 + 1476225 = 1086^2 + 1215^2 .

It is not a de Polignac number, because 2655621 - 2¹³ = 2647429 is a prime.

It is a Duffinian number.

2655621 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2655623) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2091 + ... + 3111.

2^2655621 is an apocalyptic number.

It is an amenable number.

2655621 is a deficient number, since it is larger than the sum of its proper divisors (1423181).

2655621 is a wasteful number, since it uses less digits than its factorization.

2655621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1061 (or 1041 counting only the distinct ones).

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

The square root of 2655621 is about 1629.6076214844. The cubic root of 2655621 is about 138.4805239636.

It can be divided in two parts, 265 and 5621, that added together give a triangular number (5886 = T₁₀₈).

The spelling of 2655621 in words is "two million, six hundred fifty-five thousand, six hundred twenty-one".