9218561 has 16 divisors (see below), whose sum is σ = 10644480. Its totient is φ = 7901520.

The previous prime is 9218557. The next prime is 9218581. The reversal of 9218561 is 1658129.

It is not a de Polignac number, because 9218561 - 2² = 9218557 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (9218551) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20780 + ... + 21218.

It is an arithmetic number, because the mean of its divisors is an integer number (665280).

Almost surely, 2^9218561 is an apocalyptic number.

It is an amenable number.

9218561 is a deficient number, since it is larger than the sum of its proper divisors (1425919).

9218561 is a wasteful number, since it uses less digits than its factorization.

9218561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 556.

The product of its digits is 4320, while the sum is 32.

The square root of 9218561 is about 3036.2083261858. The cubic root of 9218561 is about 209.6787302205.

It can be divided in two parts, 9218 and 561, that added together give a palindrome (9779).

The spelling of 9218561 in words is "nine million, two hundred eighteen thousand, five hundred sixty-one".