252240421 has 2 divisors, whose sum is σ = 252240422. Its totient is φ = 252240420.

The previous prime is 252240377. The next prime is 252240431. The reversal of 252240421 is 124042252.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 223831521 + 28408900 = 14961^2 + 5330^2 .

It is a cyclic number.

It is not a de Polignac number, because 252240421 - 2⁷ = 252240293 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 252240392 and 252240401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (252240431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 126120210 + 126120211.

It is an arithmetic number, because the mean of its divisors is an integer number (126120211).

Almost surely, 2^252240421 is an apocalyptic number.

It is an amenable number.

252240421 is a deficient number, since it is larger than the sum of its proper divisors (1).

252240421 is an equidigital number, since it uses as much as digits as its factorization.

252240421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1280, while the sum is 22.

The square root of 252240421 is about 15882.0786108116. The cubic root of 252240421 is about 631.8367670157.

Adding to 252240421 its reverse (124042252), we get a palindrome (376282673).

The spelling of 252240421 in words is "two hundred fifty-two million, two hundred forty thousand, four hundred twenty-one".