660004491 has 4 divisors (see below), whose sum is σ = 880005992. Its totient is φ = 440002992.

The previous prime is 660004489. The next prime is 660004493. The reversal of 660004491 is 194400066.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (660004489) and next prime (660004493).

It is not a de Polignac number, because 660004491 - 2¹ = 660004489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660004493) 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, 110000746 + ... + 110000751.

It is an arithmetic number, because the mean of its divisors is an integer number (220001498).

Almost surely, 2^660004491 is an apocalyptic number.

660004491 is a deficient number, since it is larger than the sum of its proper divisors (220001501).

660004491 is a wasteful number, since it uses less digits than its factorization.

660004491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220001500.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 660004491 is about 25690.5525631505. The cubic root of 660004491 is about 870.6607439253.

The spelling of 660004491 in words is "six hundred sixty million, four thousand, four hundred ninety-one".