661297 has 16 divisors (see below), whose sum is σ = 837760. Its totient is φ = 511056.

The previous prime is 661267. The next prime is 661321. The reversal of 661297 is 792166.

It is a de Polignac number, because none of the positive numbers 2^k-661297 is a prime.

It is an Ulam number.

Its product of digits (4536) is a multiple of the sum of its prime divisors (63).

It is not an unprimeable number, because it can be changed into a prime (661217) 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, 15358 + ... + 15400.

It is an arithmetic number, because the mean of its divisors is an integer number (52360).

2⁶⁶¹²⁹⁷ is an apocalyptic number.

It is an amenable number.

661297 is a deficient number, since it is larger than the sum of its proper divisors (176463).

661297 is an equidigital number, since it uses as much as digits as its factorization.

661297 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89 (or 63 counting only the distinct ones).

The product of its digits is 4536, while the sum is 31.

The square root of 661297 is about 813.2016969977. The cubic root of 661297 is about 87.1228721399.

The spelling of 661297 in words is "six hundred sixty-one thousand, two hundred ninety-seven".