42440731 has 4 divisors (see below), whose sum is σ = 42746200. Its totient is φ = 42135264.

The previous prime is 42440719. The next prime is 42440743. The reversal of 42440731 is 13704424.

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

It is an interprime number because it is at equal distance from previous prime (42440719) and next prime (42440743).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42440731 is a prime.

It is a super-2 number, since 2×42440731² = 3602431295628722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 42440696 and 42440705.

It is not an unprimeable number, because it can be changed into a prime (42440771) 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, 152526 + ... + 152803.

It is an arithmetic number, because the mean of its divisors is an integer number (10686550).

Almost surely, 2^42440731 is an apocalyptic number.

42440731 is a deficient number, since it is larger than the sum of its proper divisors (305469).

42440731 is a wasteful number, since it uses less digits than its factorization.

42440731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305468.

The product of its (nonzero) digits is 2688, while the sum is 25.

The square root of 42440731 is about 6514.6550944774. The cubic root of 42440731 is about 348.8143033923.

The spelling of 42440731 in words is "forty-two million, four hundred forty thousand, seven hundred thirty-one".