1681357 has 4 divisors (see below), whose sum is σ = 1702720. Its totient is φ = 1659996.

The previous prime is 1681349. The next prime is 1681363. The reversal of 1681357 is 7531861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1681357 - 2³ = 1681349 is a prime.

It is a super-2 number, since 2×1681357² = 5653922722898, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10563 + ... + 10720.

It is an arithmetic number, because the mean of its divisors is an integer number (425680).

2^1681357 is an apocalyptic number.

It is an amenable number.

1681357 is a deficient number, since it is larger than the sum of its proper divisors (21363).

1681357 is an equidigital number, since it uses as much as digits as its factorization.

1681357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21362.

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

The square root of 1681357 is about 1296.6715081315. The cubic root of 1681357 is about 118.9104379892.

The spelling of 1681357 in words is "one million, six hundred eighty-one thousand, three hundred fifty-seven".