42172581 has 8 divisors (see below), whose sum is σ = 61341984. Its totient is φ = 25559120.

The previous prime is 42172541. The next prime is 42172591. The reversal of 42172581 is 18527124.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 42172581 - 2⁷ = 42172453 is a prime.

It is a super-2 number, since 2×42172581² = 3557053176403122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42172511) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 638946 + ... + 639011.

It is an arithmetic number, because the mean of its divisors is an integer number (7667748).

Almost surely, 2^42172581 is an apocalyptic number.

It is an amenable number.

42172581 is a deficient number, since it is larger than the sum of its proper divisors (19169403).

42172581 is a wasteful number, since it uses less digits than its factorization.

42172581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1277971.

The product of its digits is 4480, while the sum is 30.

The square root of 42172581 is about 6494.0419616753. The cubic root of 42172581 is about 348.0781219116.

The spelling of 42172581 in words is "forty-two million, one hundred seventy-two thousand, five hundred eighty-one".