42405251 has 16 divisors (see below), whose sum is σ = 49368000. Its totient is φ = 35676288.

The previous prime is 42405197. The next prime is 42405269. The reversal of 42405251 is 15250424.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 42405251 - 2¹⁰ = 42404227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42405271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113501 + ... + 113873.

It is an arithmetic number, because the mean of its divisors is an integer number (3085500).

Almost surely, 2^42405251 is an apocalyptic number.

42405251 is a deficient number, since it is larger than the sum of its proper divisors (6962749).

42405251 is a wasteful number, since it uses less digits than its factorization.

42405251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 638.

The product of its (nonzero) digits is 1600, while the sum is 23.

The square root of 42405251 is about 6511.9314339142. The cubic root of 42405251 is about 348.7170746099.

Adding to 42405251 its reverse (15250424), we get a palindrome (57655675).

The spelling of 42405251 in words is "forty-two million, four hundred five thousand, two hundred fifty-one".