660191281 has 8 divisors (see below), whose sum is σ = 674616960. Its totient is φ = 645781488.

The previous prime is 660191263. The next prime is 660191321. The reversal of 660191281 is 182191066.

660191281 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 660191281 - 2⁵ = 660191249 is a prime.

It is a super-2 number, since 2×660191281² = 871705055016841922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660191251) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124635 + ... + 129823.

It is an arithmetic number, because the mean of its divisors is an integer number (84327120).

Almost surely, 2^660191281 is an apocalyptic number.

It is an amenable number.

660191281 is a deficient number, since it is larger than the sum of its proper divisors (14425679).

660191281 is a wasteful number, since it uses less digits than its factorization.

660191281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7943.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 660191281 is about 25694.1876890475. The cubic root of 660191281 is about 870.7428723465.

The spelling of 660191281 in words is "six hundred sixty million, one hundred ninety-one thousand, two hundred eighty-one".