1681573 has 2 divisors, whose sum is σ = 1681574. Its totient is φ = 1681572.

The previous prime is 1681571. The next prime is 1681579. The reversal of 1681573 is 3751861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1249924 + 431649 = 1118^2 + 657^2 .

It is an emirp because it is prime and its reverse (3751861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1681573 - 2¹ = 1681571 is a prime.

Together with 1681571, it forms a pair of twin primes.

It is a plaindrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1681571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840786 + 840787.

It is an arithmetic number, because the mean of its divisors is an integer number (840787).

2^1681573 is an apocalyptic number.

It is an amenable number.

1681573 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681573 is an equidigital number, since it uses as much as digits as its factorization.

1681573 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 31.

The square root of 1681573 is about 1296.7547956341. The cubic root of 1681573 is about 118.9155298197.

The spelling of 1681573 in words is "one million, six hundred eighty-one thousand, five hundred seventy-three".