42173251 has 2 divisors, whose sum is σ = 42173252. Its totient is φ = 42173250.

The previous prime is 42173249. The next prime is 42173267. The reversal of 42173251 is 15237124.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42173251 - 2¹ = 42173249 is a prime.

Together with 42173249, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (42173231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21086625 + 21086626.

It is an arithmetic number, because the mean of its divisors is an integer number (21086626).

Almost surely, 2^42173251 is an apocalyptic number.

42173251 is a deficient number, since it is larger than the sum of its proper divisors (1).

42173251 is an equidigital number, since it uses as much as digits as its factorization.

42173251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1680, while the sum is 25.

The square root of 42173251 is about 6494.0935472166. The cubic root of 42173251 is about 348.0799652191.

It can be divided in two parts, 42173 and 251, that added together give a palindrome (42424).

The spelling of 42173251 in words is "forty-two million, one hundred seventy-three thousand, two hundred fifty-one".