2861661 has 16 divisors (see below), whose sum is σ = 4408128. Its totient is φ = 1632000.

The previous prime is 2861659. The next prime is 2861669. The reversal of 2861661 is 1661682.

It is not a de Polignac number, because 2861661 - 2¹ = 2861659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2861669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1990 + ... + 3111.

It is an arithmetic number, because the mean of its divisors is an integer number (275508).

2^2861661 is an apocalyptic number.

It is an amenable number.

2861661 is a deficient number, since it is larger than the sum of its proper divisors (1546467).

2861661 is a wasteful number, since it uses less digits than its factorization.

2861661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5132.

The product of its digits is 3456, while the sum is 30.

The square root of 2861661 is about 1691.6444661926. The cubic root of 2861661 is about 141.9730987855.

The spelling of 2861661 in words is "two million, eight hundred sixty-one thousand, six hundred sixty-one".