2678661 has 6 divisors (see below), whose sum is σ = 3869190. Its totient is φ = 1785768.

The previous prime is 2678651. The next prime is 2678681. The reversal of 2678661 is 1668762.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1988100 + 690561 = 1410^2 + 831^2 .

It is not a de Polignac number, because 2678661 - 2⁵ = 2678629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2678651) 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, 148806 + ... + 148823.

It is an arithmetic number, because the mean of its divisors is an integer number (644865).

2^2678661 is an apocalyptic number.

It is an amenable number.

2678661 is a deficient number, since it is larger than the sum of its proper divisors (1190529).

2678661 is a wasteful number, since it uses less digits than its factorization.

2678661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297635 (or 297632 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 2678661 is about 1636.6615410646. The cubic root of 2678661 is about 138.8798540849.

It can be divided in two parts, 26 and 78661, that added together give a palindrome (78687).

The spelling of 2678661 in words is "two million, six hundred seventy-eight thousand, six hundred sixty-one".