243991224 has 64 divisors (see below), whose sum is σ = 690573600. Its totient is φ = 79792128.

The previous prime is 243991207. The next prime is 243991243. The reversal of 243991224 is 422199342.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 792 + ... + 22104.

Almost surely, 2^243991224 is an apocalyptic number.

243991224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 243991224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (345286800).

243991224 is an abundant number, since it is smaller than the sum of its proper divisors (446582376).

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

243991224 is a wasteful number, since it uses less digits than its factorization.

243991224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21381 (or 21371 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 243991224 is about 15620.2184363728. The cubic root of 243991224 is about 624.8724851324.

The spelling of 243991224 in words is "two hundred forty-three million, nine hundred ninety-one thousand, two hundred twenty-four".