2787661 has 4 divisors (see below), whose sum is σ = 2934400. Its totient is φ = 2640924.

The previous prime is 2787649. The next prime is 2787689. The reversal of 2787661 is 1667872.

2787661 = 374² + 375² + ... + 392².

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 2787661 - 2⁹ = 2787149 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2787661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2787601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73341 + ... + 73378.

It is an arithmetic number, because the mean of its divisors is an integer number (733600).

2^2787661 is an apocalyptic number.

It is an amenable number.

2787661 is a deficient number, since it is larger than the sum of its proper divisors (146739).

2787661 is a wasteful number, since it uses less digits than its factorization.

2787661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146738.

The product of its digits is 28224, while the sum is 37.

The square root of 2787661 is about 1669.6290007064. The cubic root of 2787661 is about 140.7386301990.

The spelling of 2787661 in words is "two million, seven hundred eighty-seven thousand, six hundred sixty-one".