6661257 has 4 divisors (see below), whose sum is σ = 8881680. Its totient is φ = 4440836.

The previous prime is 6661243. The next prime is 6661273. The reversal of 6661257 is 7521666.

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 a cyclic number.

It is not a de Polignac number, because 6661257 - 2¹⁰ = 6660233 is a prime.

It is a D-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 3 ways as a sum of consecutive naturals, for example, 1110207 + ... + 1110212.

It is an arithmetic number, because the mean of its divisors is an integer number (2220420).

Almost surely, 2^6661257 is an apocalyptic number.

It is an amenable number.

6661257 is a deficient number, since it is larger than the sum of its proper divisors (2220423).

6661257 is a wasteful number, since it uses less digits than its factorization.

6661257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2220422.

The product of its digits is 15120, while the sum is 33.

The square root of 6661257 is about 2580.9411074257. The cubic root of 6661257 is about 188.1562850881.

The spelling of 6661257 in words is "six million, six hundred sixty-one thousand, two hundred fifty-seven".