6661287 has 6 divisors (see below), whose sum is σ = 9621872. Its totient is φ = 4440852.

The previous prime is 6661279. The next prime is 6661301. The reversal of 6661287 is 7821666.

It is a happy number.

It is not a de Polignac number, because 6661287 - 2³ = 6661279 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661217) 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, 370063 + ... + 370080.

Almost surely, 2^6661287 is an apocalyptic number.

6661287 is a deficient number, since it is larger than the sum of its proper divisors (2960585).

6661287 is a wasteful number, since it uses less digits than its factorization.

6661287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 740149 (or 740146 counting only the distinct ones).

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

The square root of 6661287 is about 2580.9469192527. The cubic root of 6661287 is about 188.1565675514.

It can be divided in two parts, 666 and 1287, that added together give a triangular number (1953 = T₆₂).

The spelling of 6661287 in words is "six million, six hundred sixty-one thousand, two hundred eighty-seven".