660534681 has 4 divisors (see below), whose sum is σ = 880712912. Its totient is φ = 440356452.

The previous prime is 660534673. The next prime is 660534689. The reversal of 660534681 is 186435066.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (660534673) and next prime (660534689).

It is not a de Polignac number, because 660534681 - 2³ = 660534673 is a prime.

It is a super-2 number, since 2×660534681² = 872612129607543522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660534689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110089111 + ... + 110089116.

It is an arithmetic number, because the mean of its divisors is an integer number (220178228).

Almost surely, 2^660534681 is an apocalyptic number.

It is an amenable number.

660534681 is a deficient number, since it is larger than the sum of its proper divisors (220178231).

660534681 is a wasteful number, since it uses less digits than its factorization.

660534681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220178230.

The product of its (nonzero) digits is 103680, while the sum is 39.

The square root of 660534681 is about 25700.8692654548. The cubic root of 660534681 is about 870.8938191412.

The spelling of 660534681 in words is "six hundred sixty million, five hundred thirty-four thousand, six hundred eighty-one".