240642421 has 2 divisors, whose sum is σ = 240642422. Its totient is φ = 240642420.

The previous prime is 240642403. The next prime is 240642433. The reversal of 240642421 is 124246042.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 236698225 + 3944196 = 15385^2 + 1986^2 .

It is a cyclic number.

It is not a de Polignac number, because 240642421 - 2¹¹ = 240640373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (240742421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 120321210 + 120321211.

It is an arithmetic number, because the mean of its divisors is an integer number (120321211).

Almost surely, 2^240642421 is an apocalyptic number.

It is an amenable number.

240642421 is a deficient number, since it is larger than the sum of its proper divisors (1).

240642421 is an equidigital number, since it uses as much as digits as its factorization.

240642421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3072, while the sum is 25.

The square root of 240642421 is about 15512.6535769996. The cubic root of 240642421 is about 622.0004936876. Note that the first 3 decimals are identical.

Adding to 240642421 its reverse (124246042), we get a palindrome (364888463).

The spelling of 240642421 in words is "two hundred forty million, six hundred forty-two thousand, four hundred twenty-one".