1691055851 has 2 divisors, whose sum is σ = 1691055852. Its totient is φ = 1691055850.

The previous prime is 1691055829. The next prime is 1691055853. The reversal of 1691055851 is 1585501961.

It is a strong prime.

It is an emirp because it is prime and its reverse (1585501961) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1691055851 is a prime.

It is a super-3 number, since 3×1691055851³ (a number of 29 digits) contains 333 as substring.

Together with 1691055853, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1691055799 and 1691055808.

It is not a weakly prime, because it can be changed into another prime (1691055853) 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, 845527925 + 845527926.

It is an arithmetic number, because the mean of its divisors is an integer number (845527926).

Almost surely, 2^1691055851 is an apocalyptic number.

1691055851 is a deficient number, since it is larger than the sum of its proper divisors (1).

1691055851 is an equidigital number, since it uses as much as digits as its factorization.

1691055851 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54000, while the sum is 41.

The square root of 1691055851 is about 41122.4494771408. The cubic root of 1691055851 is about 1191.3864336528.

The spelling of 1691055851 in words is "one billion, six hundred ninety-one million, fifty-five thousand, eight hundred fifty-one".