655887681 has 12 divisors (see below), whose sum is σ = 949083408. Its totient is φ = 436478424.

The previous prime is 655887653. The next prime is 655887689. The reversal of 655887681 is 186788556.

655887681 is a `hidden beast` number, since 6 + 558 + 8 + 7 + 6 + 81 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-655887681 is a prime.

It is a super-2 number, since 2×655887681² = 860377300175115522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (655887689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 59655 + ... + 69788.

It is an arithmetic number, because the mean of its divisors is an integer number (79090284).

Almost surely, 2^655887681 is an apocalyptic number.

It is an amenable number.

655887681 is a deficient number, since it is larger than the sum of its proper divisors (293195727).

655887681 is a wasteful number, since it uses less digits than its factorization.

655887681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130012 (or 130009 counting only the distinct ones).

The product of its digits is 3225600, while the sum is 54.

The square root of 655887681 is about 25610.3041957725. The cubic root of 655887681 is about 868.8467040980.

The spelling of 655887681 in words is "six hundred fifty-five million, eight hundred eighty-seven thousand, six hundred eighty-one".