42172523 has 2 divisors, whose sum is σ = 42172524. Its totient is φ = 42172522.

The previous prime is 42172519. The next prime is 42172531. The reversal of 42172523 is 32527124.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42172523 - 2² = 42172519 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 42172492 and 42172501.

It is not a weakly prime, because it can be changed into another prime (42174523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21086261 + 21086262.

It is an arithmetic number, because the mean of its divisors is an integer number (21086262).

Almost surely, 2^42172523 is an apocalyptic number.

42172523 is a deficient number, since it is larger than the sum of its proper divisors (1).

42172523 is an equidigital number, since it uses as much as digits as its factorization.

42172523 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3360, while the sum is 26.

The square root of 42172523 is about 6494.0374960420. The cubic root of 42172523 is about 348.0779623408.

Adding to 42172523 its reverse (32527124), we get a palindrome (74699647).

The spelling of 42172523 in words is "forty-two million, one hundred seventy-two thousand, five hundred twenty-three".