42172505 has 4 divisors (see below), whose sum is σ = 50607012. Its totient is φ = 33738000.

The previous prime is 42172483. The next prime is 42172511. The reversal of 42172505 is 50527124.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14462809 + 27709696 = 3803^2 + 5264^2 .

It is not a de Polignac number, because 42172505 - 2¹⁶ = 42106969 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4217246 + ... + 4217255.

It is an arithmetic number, because the mean of its divisors is an integer number (12651753).

Almost surely, 2^42172505 is an apocalyptic number.

It is an amenable number.

42172505 is a deficient number, since it is larger than the sum of its proper divisors (8434507).

42172505 is an equidigital number, since it uses as much as digits as its factorization.

42172505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8434506.

The product of its (nonzero) digits is 2800, while the sum is 26.

The square root of 42172505 is about 6494.0361101552. The cubic root of 42172505 is about 348.0779128188.

Adding to 42172505 its reverse (50527124), we get a palindrome (92699629).

The spelling of 42172505 in words is "forty-two million, one hundred seventy-two thousand, five hundred five".