667448491 has 4 divisors (see below), whose sum is σ = 667504152. Its totient is φ = 667392832.

The previous prime is 667448437. The next prime is 667448497. The reversal of 667448491 is 194844766.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 194844766 = 2 ⋅97422383.

It is a cyclic number.

It is not a de Polignac number, because 667448491 - 2¹¹ = 667446443 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667448497) 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, 1606 + ... + 36571.

It is an arithmetic number, because the mean of its divisors is an integer number (166876038).

Almost surely, 2^667448491 is an apocalyptic number.

667448491 is a deficient number, since it is larger than the sum of its proper divisors (55661).

667448491 is a wasteful number, since it uses less digits than its factorization.

667448491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55660.

The product of its digits is 1161216, while the sum is 49.

The square root of 667448491 is about 25835.0245016334. The cubic root of 667448491 is about 873.9218245616.

The spelling of 667448491 in words is "six hundred sixty-seven million, four hundred forty-eight thousand, four hundred ninety-one".