6661577 has 4 divisors (see below), whose sum is σ = 7174020. Its totient is φ = 6149136.

The previous prime is 6661553. The next prime is 6661583. The reversal of 6661577 is 7751666.

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

It can be written as a sum of positive squares in 2 ways, for example, as 978121 + 5683456 = 989^2 + 2384^2 .

It is a cyclic number.

It is not a de Polignac number, because 6661577 - 2¹⁰ = 6660553 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 6661577.

It is not an unprimeable number, because it can be changed into a prime (6661547) 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, 256202 + ... + 256227.

It is an arithmetic number, because the mean of its divisors is an integer number (1793505).

Almost surely, 2^6661577 is an apocalyptic number.

It is an amenable number.

6661577 is a deficient number, since it is larger than the sum of its proper divisors (512443).

6661577 is a wasteful number, since it uses less digits than its factorization.

6661577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 512442.

The product of its digits is 52920, while the sum is 38.

The square root of 6661577 is about 2581.0030995719. The cubic root of 6661577 is about 188.1592979853.

The spelling of 6661577 in words is "six million, six hundred sixty-one thousand, five hundred seventy-seven".