42516251 has 2 divisors, whose sum is σ = 42516252. Its totient is φ = 42516250.

The previous prime is 42516241. The next prime is 42516301. The reversal of 42516251 is 15261524.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42516251 is a prime.

It is equal to p_2577131 and since 42516251 and 2577131 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 42516251.

It is not a weakly prime, because it can be changed into another prime (42516211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21258125 + 21258126.

It is an arithmetic number, because the mean of its divisors is an integer number (21258126).

Almost surely, 2^42516251 is an apocalyptic number.

42516251 is a deficient number, since it is larger than the sum of its proper divisors (1).

42516251 is an equidigital number, since it uses as much as digits as its factorization.

42516251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2400, while the sum is 26.

The square root of 42516251 is about 6520.4486808808. The cubic root of 42516251 is about 349.0210768244.

Adding to 42516251 its reverse (15261524), we get a palindrome (57777775).

The spelling of 42516251 in words is "forty-two million, five hundred sixteen thousand, two hundred fifty-one".