42457581 has 16 divisors (see below), whose sum is σ = 63237120. Its totient is φ = 28153440.

The previous prime is 42457567. The next prime is 42457601. The reversal of 42457581 is 18575424.

42457581 is a `hidden beast` number, since 4 + 2 + 4 + 575 + 81 = 666.

It is not a de Polignac number, because 42457581 - 2⁵ = 42457549 is a prime.

It is a super-2 number, since 2×42457581² = 3605292368743122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42457501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1041 + ... + 9273.

It is an arithmetic number, because the mean of its divisors is an integer number (3952320).

Almost surely, 2^42457581 is an apocalyptic number.

It is an amenable number.

42457581 is a deficient number, since it is larger than the sum of its proper divisors (20779539).

42457581 is a wasteful number, since it uses less digits than its factorization.

42457581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8433 (or 8427 counting only the distinct ones).

The product of its digits is 44800, while the sum is 36.

The square root of 42457581 is about 6515.9482042140. The cubic root of 42457581 is about 348.8604598652.

The spelling of 42457581 in words is "forty-two million, four hundred fifty-seven thousand, five hundred eighty-one".