42557731 has 4 divisors (see below), whose sum is σ = 42709464. Its totient is φ = 42406000.

The previous prime is 42557707. The next prime is 42557737. The reversal of 42557731 is 13775524.

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

It is a cyclic number.

It is not a de Polignac number, because 42557731 - 2²¹ = 40460579 is a prime.

It is a super-2 number, since 2×42557731² = 3622320935736722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42557737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75445 + ... + 76006.

It is an arithmetic number, because the mean of its divisors is an integer number (10677366).

Almost surely, 2^42557731 is an apocalyptic number.

42557731 is a deficient number, since it is larger than the sum of its proper divisors (151733).

42557731 is a wasteful number, since it uses less digits than its factorization.

42557731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151732.

The product of its digits is 29400, while the sum is 34.

The square root of 42557731 is about 6523.6286681570. The cubic root of 42557731 is about 349.1345447204.

The spelling of 42557731 in words is "forty-two million, five hundred fifty-seven thousand, seven hundred thirty-one".