2661866 has 4 divisors (see below), whose sum is σ = 3992802. Its totient is φ = 1330932.

The previous prime is 2661863. The next prime is 2661871. The reversal of 2661866 is 6681662.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 2627641 + 34225 = 1621^2 + 185^2 .

It is a plaindrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (2661863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665465 + ... + 665468.

2^2661866 is an apocalyptic number.

2661866 is a deficient number, since it is larger than the sum of its proper divisors (1330936).

2661866 is a wasteful number, since it uses less digits than its factorization.

2661866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1330935.

The product of its digits is 20736, while the sum is 35.

The square root of 2661866 is about 1631.5226017435. The cubic root of 2661866 is about 138.5889899753.

The spelling of 2661866 in words is "two million, six hundred sixty-one thousand, eight hundred sixty-six".