1681597 has 2 divisors, whose sum is σ = 1681598. Its totient is φ = 1681596.

The previous prime is 1681591. The next prime is 1681619. The reversal of 1681597 is 7951861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1285956 + 395641 = 1134^2 + 629^2 .

It is a cyclic number.

It is not a de Polignac number, because 1681597 - 2⁷ = 1681469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1681591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840798 + 840799.

It is an arithmetic number, because the mean of its divisors is an integer number (840799).

2^1681597 is an apocalyptic number.

It is an amenable number.

1681597 is a deficient number, since it is larger than the sum of its proper divisors (1).

1681597 is an equidigital number, since it uses as much as digits as its factorization.

1681597 is an evil number, because the sum of its binary digits is even.

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

The square root of 1681597 is about 1296.7640494708. The cubic root of 1681597 is about 118.9160955518.

It can be divided in two parts, 1681 and 597, that added together give a triangular number (2278 = T₆₇).

The spelling of 1681597 in words is "one million, six hundred eighty-one thousand, five hundred ninety-seven".