22218529 has 12 divisors (see below), whose sum is σ = 23520196. Its totient is φ = 20984832.

The previous prime is 22218509. The next prime is 22218551. The reversal of 22218529 is 92581222.

It can be written as a sum of positive squares in 2 ways, for example, as 5832225 + 16386304 = 2415^2 + 4048^2 .

It is not a de Polignac number, because 22218529 - 2¹³ = 22210337 is a prime.

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

It is a Duffinian number.

22218529 is a Rhonda number in base 10.

Its product of digits (5760) is a multiple of the sum of its prime factors (576).

It is a self number, because there is not a number n which added to its sum of digits gives 22218529.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22218509) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 51097 + ... + 51529.

Almost surely, 2^22218529 is an apocalyptic number.

It is an amenable number.

22218529 is a deficient number, since it is larger than the sum of its proper divisors (1301667).

22218529 is an equidigital number, since it uses as much as digits as its factorization.

22218529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576 (or 553 counting only the distinct ones).

The product of its digits is 5760, while the sum is 31.

The square root of 22218529 is about 4713.6534662616. The cubic root of 22218529 is about 281.1286459830.

The spelling of 22218529 in words is "twenty-two million, two hundred eighteen thousand, five hundred twenty-nine".