242405531 has 4 divisors (see below), whose sum is σ = 246023592. Its totient is φ = 238787472.

The previous prime is 242405507. The next prime is 242405539. The reversal of 242405531 is 135504242.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 135504242 = 2 ⋅67752121.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-242405531 is a prime.

It is a super-2 number, since 2×242405531² = 117520882918783922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 242405531.

It is not an unprimeable number, because it can be changed into a prime (242405539) 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, 1808930 + ... + 1809063.

It is an arithmetic number, because the mean of its divisors is an integer number (61505898).

Almost surely, 2^242405531 is an apocalyptic number.

242405531 is a deficient number, since it is larger than the sum of its proper divisors (3618061).

242405531 is an equidigital number, since it uses as much as digits as its factorization.

242405531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3618060.

The product of its (nonzero) digits is 4800, while the sum is 26.

The square root of 242405531 is about 15569.3779901446. The cubic root of 242405531 is about 623.5158649922.

Adding to 242405531 its reverse (135504242), we get a palindrome (377909773).

The spelling of 242405531 in words is "two hundred forty-two million, four hundred five thousand, five hundred thirty-one".