660647057 has 12 divisors (see below), whose sum is σ = 795009780. Its totient is φ = 546741216.

The previous prime is 660647023. The next prime is 660647069. The reversal of 660647057 is 750746066.

It can be written as a sum of positive squares in 2 ways, for example, as 545642881 + 115004176 = 23359^2 + 10724^2 .

It is not a de Polignac number, because 660647057 - 2¹⁴ = 660630673 is a prime.

It is a super-2 number, since 2×660647057² = 872909067845522498, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660647257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 231038 + ... + 233879.

It is an arithmetic number, because the mean of its divisors is an integer number (66250815).

Almost surely, 2^660647057 is an apocalyptic number.

It is an amenable number.

660647057 is a deficient number, since it is larger than the sum of its proper divisors (134362723).

660647057 is a wasteful number, since it uses less digits than its factorization.

660647057 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 464960 (or 464953 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 41.

The square root of 660647057 is about 25703.0554020334. The cubic root of 660647057 is about 870.9432043928.

Subtracting 660647057 from its reverse (750746066), we obtain a palindrome (90099009).

The spelling of 660647057 in words is "six hundred sixty million, six hundred forty-seven thousand, fifty-seven".