243021431 has 4 divisors (see below), whose sum is σ = 250860864. Its totient is φ = 235182000.

The previous prime is 243021403. The next prime is 243021451. The reversal of 243021431 is 134120342.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 134120342 = 2 ⋅67060171.

It is a cyclic number.

It is not a de Polignac number, because 243021431 - 2¹⁸ = 242759287 is a prime.

It is a super-2 number, since 2×243021431² = 118118831850575522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243021451) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3919670 + ... + 3919731.

It is an arithmetic number, because the mean of its divisors is an integer number (62715216).

Almost surely, 2^243021431 is an apocalyptic number.

243021431 is a deficient number, since it is larger than the sum of its proper divisors (7839433).

243021431 is an equidigital number, since it uses as much as digits as its factorization.

243021431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7839432.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 243021431 is about 15589.1446526100. The cubic root of 243021431 is about 624.0434913460.

Adding to 243021431 its reverse (134120342), we get a palindrome (377141773).

The spelling of 243021431 in words is "two hundred forty-three million, twenty-one thousand, four hundred thirty-one".