897661 has 4 divisors (see below), whose sum is σ = 914652. Its totient is φ = 880672.

The previous prime is 897649. The next prime is 897671. The reversal of 897661 is 166798.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 166798 = 2 ⋅83399.

It can be written as a sum of positive squares in 2 ways, for example, as 481636 + 416025 = 694^2 + 645^2 .

It is a cyclic number.

It is not a de Polignac number, because 897661 - 2⁵ = 897629 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 897661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (897601) 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, 8416 + ... + 8521.

It is an arithmetic number, because the mean of its divisors is an integer number (228663).

2⁸⁹⁷⁶⁶¹ is an apocalyptic number.

It is an amenable number.

897661 is a deficient number, since it is larger than the sum of its proper divisors (16991).

897661 is a wasteful number, since it uses less digits than its factorization.

897661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16990.

The product of its digits is 18144, while the sum is 37.

The square root of 897661 is about 947.4497348145. The cubic root of 897661 is about 96.4652259110.

It can be divided in two parts, 89 and 7661, that added together give a triangular number (7750 = T₁₂₄).

The spelling of 897661 in words is "eight hundred ninety-seven thousand, six hundred sixty-one".