661797 has 16 divisors (see below), whose sum is σ = 993280. Its totient is φ = 435456.

The previous prime is 661777. The next prime is 661823. The reversal of 661797 is 797166.

It is not a de Polignac number, because 661797 - 2⁸ = 661541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661777) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3333 + ... + 3525.

It is an arithmetic number, because the mean of its divisors is an integer number (62080).

2⁶⁶¹⁷⁹⁷ is an apocalyptic number.

It is an amenable number.

661797 is a deficient number, since it is larger than the sum of its proper divisors (331483).

661797 is a wasteful number, since it uses less digits than its factorization.

661797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329 (or 323 counting only the distinct ones).

The product of its digits is 15876, while the sum is 36.

The square root of 661797 is about 813.5090657147. The cubic root of 661797 is about 87.1448241836.

The spelling of 661797 in words is "six hundred sixty-one thousand, seven hundred ninety-seven".