42090831 has 6 divisors (see below), whose sum is σ = 60797880. Its totient is φ = 28060548.

The previous prime is 42090821. The next prime is 42090857. The reversal of 42090831 is 13809024.

It is not a de Polignac number, because 42090831 - 2⁹ = 42090319 is a prime.

It is a super-2 number, since 2×42090831² = 3543276108541122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 42090795 and 42090804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42090821) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2338371 + ... + 2338388.

It is an arithmetic number, because the mean of its divisors is an integer number (10132980).

Almost surely, 2^42090831 is an apocalyptic number.

42090831 is a deficient number, since it is larger than the sum of its proper divisors (18707049).

42090831 is a wasteful number, since it uses less digits than its factorization.

42090831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4676765 (or 4676762 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 42090831 is about 6487.7446774669. The cubic root of 42090831 is about 347.8530642067.

Adding to 42090831 its reverse (13809024), we get a palindrome (55899855).

The spelling of 42090831 in words is "forty-two million, ninety thousand, eight hundred thirty-one".