665491487 has 4 divisors (see below), whose sum is σ = 665594616. Its totient is φ = 665388360.

The previous prime is 665491483. The next prime is 665491513. The reversal of 665491487 is 784194566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 784194566 = 2 ⋅392097283.

It is a cyclic number.

It is not a de Polignac number, because 665491487 - 2² = 665491483 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 (665491481) 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, 41189 + ... + 55022.

It is an arithmetic number, because the mean of its divisors is an integer number (166398654).

Almost surely, 2^665491487 is an apocalyptic number.

665491487 is a deficient number, since it is larger than the sum of its proper divisors (103129).

665491487 is an equidigital number, since it uses as much as digits as its factorization.

665491487 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103128.

The product of its digits is 1451520, while the sum is 50.

The square root of 665491487 is about 25797.1216805286. The cubic root of 665491487 is about 873.0668558269.

The spelling of 665491487 in words is "six hundred sixty-five million, four hundred ninety-one thousand, four hundred eighty-seven".