42000031 has 4 divisors (see below), whose sum is σ = 43024464. Its totient is φ = 40975600.

The previous prime is 42000029. The next prime is 42000037. The reversal of 42000031 is 13000024.

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 42000031 - 2¹ = 42000029 is a prime.

It is a super-2 number, since 2×42000031² = 3528005208001922, 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 = 41999981 and 42000017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42000037) 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, 512155 + ... + 512236.

It is an arithmetic number, because the mean of its divisors is an integer number (10756116).

Almost surely, 2^42000031 is an apocalyptic number.

42000031 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

42000031 is a deficient number, since it is larger than the sum of its proper divisors (1024433).

42000031 is a wasteful number, since it uses less digits than its factorization.

42000031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1024432.

The product of its (nonzero) digits is 24, while the sum is 10.

The square root of 42000031 is about 6480.7430901093. The cubic root of 42000031 is about 347.6027500099.

Adding to 42000031 its reverse (13000024), we get a palindrome (55000055).

The spelling of 42000031 in words is "forty-two million, thirty-one", and thus it is an aban number and an uban number.