8661280 has 24 divisors (see below), whose sum is σ = 20462652. Its totient is φ = 3464448.

The previous prime is 8661253. The next prime is 8661281. The reversal of 8661280 is 821668.

It can be written as a sum of positive squares in 2 ways, for example, as 7033104 + 1628176 = 2652^2 + 1276^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (8661281) 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, 26907 + ... + 27226.

Almost surely, 2^8661280 is an apocalyptic number.

8661280 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

8661280 is an abundant number, since it is smaller than the sum of its proper divisors (11801372).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8661280 is a wasteful number, since it uses less digits than its factorization.

8661280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54148 (or 54140 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 8661280 is about 2943.0052667299. The cubic root of 8661280 is about 205.3654397800.

Subtracting from 8661280 its sum of digits (31), we obtain a square (8661249 = 2943²).

The spelling of 8661280 in words is "eight million, six hundred sixty-one thousand, two hundred eighty".