1799790991 has 2 divisors, whose sum is σ = 1799790992. Its totient is φ = 1799790990.

The previous prime is 1799790989. The next prime is 1799791033. The reversal of 1799790991 is 1990979971.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1799790991 - 2¹ = 1799790989 is a prime.

It is a super-2 number, since 2×1799790991² = 6478495222569524162, which contains 22 as substring.

Together with 1799790989, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1799790911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 899895495 + 899895496.

It is an arithmetic number, because the mean of its divisors is an integer number (899895496).

Almost surely, 2^1799790991 is an apocalyptic number.

1799790991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1799790991 is an equidigital number, since it uses as much as digits as its factorization.

1799790991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2893401, while the sum is 61.

The square root of 1799790991 is about 42423.9436049974. The cubic root of 1799790991 is about 1216.3933145160.

The spelling of 1799790991 in words is "one billion, seven hundred ninety-nine million, seven hundred ninety thousand, nine hundred ninety-one".