1681844545 has 8 divisors (see below), whose sum is σ = 2022632424. Its totient is φ = 1342529664.

The previous prime is 1681844513. The next prime is 1681844551. The reversal of 1681844545 is 5454481861.

It can be written as a sum of positive squares in 4 ways, for example, as 532363329 + 1149481216 = 23073^2 + 33904^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1681844545 - 2⁵ = 1681844513 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1681844495 and 1681844504.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 365734 + ... + 370303.

It is an arithmetic number, because the mean of its divisors is an integer number (252829053).

Almost surely, 2^1681844545 is an apocalyptic number.

It is an amenable number.

1681844545 is a deficient number, since it is larger than the sum of its proper divisors (340787879).

1681844545 is an equidigital number, since it uses as much as digits as its factorization.

1681844545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 736499.

The product of its digits is 614400, while the sum is 46.

The square root of 1681844545 is about 41010.2980359812. The cubic root of 1681844545 is about 1189.2193041006.

The spelling of 1681844545 in words is "one billion, six hundred eighty-one million, eight hundred forty-four thousand, five hundred forty-five".