222218649 has 9 divisors (see below), whose sum is σ = 321047103. Its totient is φ = 148115952.

The previous prime is 222218641. The next prime is 222218653. The reversal of 222218649 is 946812222.

The square root of 222218649 is 14907.

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

222218649 is a `hidden beast` number, since 2 + 2 + 2 + 2 + 1 + 8 + 649 = 666.

It can be written as a sum of positive squares in only one way, i.e., 44796249 + 177422400 = 6693^2 + 13320^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 222218649 - 2³ = 222218641 is a prime.

It is a super-2 number, since 2×222218649² = 98762255926770402, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (222218641) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 42237 + ... + 47205.

Almost surely, 2^222218649 is an apocalyptic number.

222218649 is the 14907-th square number.

222218649 is the 7454-th centered octagonal number.

It is an amenable number.

222218649 is a deficient number, since it is larger than the sum of its proper divisors (98828454).

222218649 is an frugal number, since it uses more digits than its factorization.

222218649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9944 (or 4972 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The cubic root of 222218649 is about 605.7036177721.

Multiplying 222218649 by its sum of digits (36), we get a square (7999871364 = 89442²).

It can be divided in two parts, 22 and 2218649, that added together give a triangular number (2218671 = T₂₁₀₆).

The spelling of 222218649 in words is "two hundred twenty-two million, two hundred eighteen thousand, six hundred forty-nine".