1610806991 has 2 divisors, whose sum is σ = 1610806992. Its totient is φ = 1610806990.

The previous prime is 1610806973. The next prime is 1610806993. The reversal of 1610806991 is 1996080161.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (1996080161) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 1669080191 and 1910809661.

It is a cyclic number.

It is not a de Polignac number, because 1610806991 - 2²² = 1606612687 is a prime.

Together with 1610806993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1610806993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 805403495 + 805403496.

It is an arithmetic number, because the mean of its divisors is an integer number (805403496).

Almost surely, 2^1610806991 is an apocalyptic number.

1610806991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1610806991 is an equidigital number, since it uses as much as digits as its factorization.

1610806991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 41.

The square root of 1610806991 is about 40134.8600470962. The cubic root of 1610806991 is about 1172.2345080772.

The spelling of 1610806991 in words is "one billion, six hundred ten million, eight hundred six thousand, nine hundred ninety-one".