1990667831 has 2 divisors, whose sum is σ = 1990667832. Its totient is φ = 1990667830.

The previous prime is 1990667827. The next prime is 1990667849. The reversal of 1990667831 is 1387660991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1990667831 - 2² = 1990667827 is a prime.

It is a super-2 number, since 2×1990667831² = 7925516826756489122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1990667831.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1990667801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 995333915 + 995333916.

It is an arithmetic number, because the mean of its divisors is an integer number (995333916).

Almost surely, 2^1990667831 is an apocalyptic number.

1990667831 is a deficient number, since it is larger than the sum of its proper divisors (1).

1990667831 is an equidigital number, since it uses as much as digits as its factorization.

1990667831 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 489888, while the sum is 50.

The square root of 1990667831 is about 44616.9007327941. The cubic root of 1990667831 is about 1257.9583613378.

The spelling of 1990667831 in words is "one billion, nine hundred ninety million, six hundred sixty-seven thousand, eight hundred thirty-one".