2721618 has 12 divisors (see below), whose sum is σ = 5896878. Its totient is φ = 907200.

The previous prime is 2721577. The next prime is 2721619. The reversal of 2721618 is 8161272.

2721618 is a `hidden beast` number, since 27 + 21 + 618 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2614689 + 106929 = 1617^2 + 327^2 .

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 2721591 and 2721600.

It is not an unprimeable number, because it can be changed into a prime (2721619) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 75583 + ... + 75618.

2^2721618 is an apocalyptic number.

2721618 is an abundant number, since it is smaller than the sum of its proper divisors (3175260).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2721618 is a wasteful number, since it uses less digits than its factorization.

2721618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151209 (or 151206 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 2721618 is about 1649.7327056223. The cubic root of 2721618 is about 139.6183140862.

The spelling of 2721618 in words is "two million, seven hundred twenty-one thousand, six hundred eighteen".