1597681 has 4 divisors (see below), whose sum is σ = 1604772. Its totient is φ = 1590592.

The previous prime is 1597679. The next prime is 1597693. The reversal of 1597681 is 1867951.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 119025 + 1478656 = 345^2 + 1216^2 .

It is a cyclic number.

It is not a de Polignac number, because 1597681 - 2¹ = 1597679 is a prime.

It is a super-2 number, since 2×1597681² = 5105169155522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1597681.

It is not an unprimeable number, because it can be changed into a prime (1597601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3196 + ... + 3661.

It is an arithmetic number, because the mean of its divisors is an integer number (401193).

2^1597681 is an apocalyptic number.

It is an amenable number.

1597681 is a deficient number, since it is larger than the sum of its proper divisors (7091).

1597681 is an equidigital number, since it uses as much as digits as its factorization.

1597681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7090.

The product of its digits is 15120, while the sum is 37.

The square root of 1597681 is about 1263.9940664418. The cubic root of 1597681 is about 116.9041755639.

It can be divided in two parts, 1597 and 681, that added together give a triangular number (2278 = T₆₇).

The spelling of 1597681 in words is "one million, five hundred ninety-seven thousand, six hundred eighty-one".