2009831 has 2 divisors, whose sum is σ = 2009832. Its totient is φ = 2009830.

The previous prime is 2009827. The next prime is 2009857. The reversal of 2009831 is 1389002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2009831 - 2² = 2009827 is a prime.

It is a super-2 number, since 2×2009831² = 8078841297122, which contains 22 as substring.

It is a Sophie Germain prime.

It is an Ulam number.

It is equal to p₁₄₉₆₂₁ and since 2009831 and 149621 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 2009797 and 2009806.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2009881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1004915 + 1004916.

It is an arithmetic number, because the mean of its divisors is an integer number (1004916).

2^2009831 is an apocalyptic number.

2009831 is a deficient number, since it is larger than the sum of its proper divisors (1).

2009831 is an equidigital number, since it uses as much as digits as its factorization.

2009831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 2009831 is about 1417.6850849184. The cubic root of 2009831 is about 126.1982057254.

The spelling of 2009831 in words is "two million, nine thousand, eight hundred thirty-one".