243921924 has 81 divisors (see below), whose sum is σ = 655524597. Its totient is φ = 76465728.

The previous prime is 243921917. The next prime is 243921947. The reversal of 243921924 is 429129342.

The square root of 243921924 is 15618.

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

243921924 is a `hidden beast` number, since 2 + 439 + 219 + 2 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 143280900 + 100641024 = 11970^2 + 10032^2 .

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 an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1780384 + ... + 1780520.

Almost surely, 2^243921924 is an apocalyptic number.

243921924 is the 15618-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 243921924

243921924 is an abundant number, since it is smaller than the sum of its proper divisors (411602673).

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

243921924 is a wasteful number, since it uses less digits than its factorization.

243921924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322 (or 161 counting only the distinct ones).

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

The cubic root of 243921924 is about 624.8133193928.

Multiplying 243921924 by its sum of digits (36), we get a square (8781189264 = 93708²).

243921924 divided by its sum of digits (36) gives a square (6775609 = 2603²).

The spelling of 243921924 in words is "two hundred forty-three million, nine hundred twenty-one thousand, nine hundred twenty-four".