1681844551 has 2 divisors, whose sum is σ = 1681844552. Its totient is φ = 1681844550.

The previous prime is 1681844513. The next prime is 1681844573. The reversal of 1681844551 is 1554481861.

It is a strong prime.

It is an emirp because it is prime and its reverse (1554481861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1681844551 - 2²⁷ = 1547626823 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1681844498 and 1681844507.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1681844651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840922275 + 840922276.

It is an arithmetic number, because the mean of its divisors is an integer number (840922276).

Almost surely, 2^1681844551 is an apocalyptic number.

1681844551 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681844551 is an equidigital number, since it uses as much as digits as its factorization.

1681844551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 153600, while the sum is 43.

The square root of 1681844551 is about 41010.2981091335. The cubic root of 1681844551 is about 1189.2193055148.

The spelling of 1681844551 in words is "one billion, six hundred eighty-one million, eight hundred forty-four thousand, five hundred fifty-one".