42705031 has 4 divisors (see below), whose sum is σ = 42723000. Its totient is φ = 42687064.

The previous prime is 42705029. The next prime is 42705049. The reversal of 42705031 is 13050724.

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 42705031 - 2¹ = 42705029 is a prime.

It is a super-2 number, since 2×42705031² = 3647439345421922, 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 = 42704993 and 42705011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42705431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4756 + ... + 10393.

It is an arithmetic number, because the mean of its divisors is an integer number (10680750).

Almost surely, 2^42705031 is an apocalyptic number.

42705031 is the 2923-rd centered decagonal number.

42705031 is a deficient number, since it is larger than the sum of its proper divisors (17969).

42705031 is a wasteful number, since it uses less digits than its factorization.

42705031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17968.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 42705031 is about 6534.9086451151. The cubic root of 42705031 is about 349.5368868076.

Adding to 42705031 its reverse (13050724), we get a palindrome (55755755).

The spelling of 42705031 in words is "forty-two million, seven hundred five thousand, thirty-one".