243031621 has 10 divisors (see below), whose sum is σ = 283522822. Its totient is φ = 208310760.

The previous prime is 243031597. The next prime is 243031697. The reversal of 243031621 is 126130342.

It can be written as a sum of positive squares in only one way, i.e., 137147521 + 105884100 = 11711^2 + 10290^2 .

It is not a de Polignac number, because 243031621 - 2⁵ = 243031589 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 243031592 and 243031601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243011621) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 48210 + ... + 53011.

Almost surely, 2^243031621 is an apocalyptic number.

It is an amenable number.

243031621 is a deficient number, since it is larger than the sum of its proper divisors (40491201).

243031621 is an frugal number, since it uses more digits than its factorization.

243031621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101249 (or 101228 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 243031621 is about 15589.4714791747. The cubic root of 243031621 is about 624.0522133673.

Adding to 243031621 its reverse (126130342), we get a palindrome (369161963).

The spelling of 243031621 in words is "two hundred forty-three million, thirty-one thousand, six hundred twenty-one".