243381521 has 8 divisors (see below), whose sum is σ = 247752000. Its totient is φ = 239023440.

The previous prime is 243381511. The next prime is 243381569. The reversal of 243381521 is 125183342.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 243381521 - 2¹⁰ = 243380497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (243381511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42380 + ... + 47778.

It is an arithmetic number, because the mean of its divisors is an integer number (30969000).

Almost surely, 2^243381521 is an apocalyptic number.

It is an amenable number.

243381521 is a deficient number, since it is larger than the sum of its proper divisors (4370479).

243381521 is an equidigital number, since it uses as much as digits as its factorization.

243381521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6199.

The product of its digits is 5760, while the sum is 29.

The square root of 243381521 is about 15600.6897603920. The cubic root of 243381521 is about 624.3515587243.

The spelling of 243381521 in words is "two hundred forty-three million, three hundred eighty-one thousand, five hundred twenty-one".