8661249 has 21 divisors (see below), whose sum is σ = 13106163. Its totient is φ = 5721192.

The previous prime is 8661241. The next prime is 8661251. The reversal of 8661249 is 9421668.

The square root of 8661249 is 2943.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 6036849 + 2624400 = 2457^2 + 1620^2 .

It is not a de Polignac number, because 8661249 - 2³ = 8661241 is a prime.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (8661241) by changing a digit.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 79407 + ... + 79515.

It is an arithmetic number, because the mean of its divisors is an integer number (624103).

Almost surely, 2^8661249 is an apocalyptic number.

8661249 is the 2943-rd square number.

8661249 is the 1472-nd centered octagonal number.

It is an amenable number.

8661249 is a deficient number, since it is larger than the sum of its proper divisors (4444914).

8661249 is an frugal number, since it uses more digits than its factorization.

8661249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236 (or 112 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The cubic root of 8661249 is about 205.3651947686.

Multiplying 8661249 by its sum of digits (36), we get a square (311804964 = 17658²).

Multiplying 8661249 by its product of digits (20736), we get a square (179599659264 = 423792²).

The spelling of 8661249 in words is "eight million, six hundred sixty-one thousand, two hundred forty-nine".