667554661 has 16 divisors (see below), whose sum is σ = 708744960. Its totient is φ = 627943680.

The previous prime is 667554653. The next prime is 667554689. The reversal of 667554661 is 166455766.

667554661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 667554661 - 2³ = 667554653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667554361) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 136881 + ... + 141673.

It is an arithmetic number, because the mean of its divisors is an integer number (44296560).

Almost surely, 2^667554661 is an apocalyptic number.

It is an amenable number.

667554661 is a deficient number, since it is larger than the sum of its proper divisors (41190299).

667554661 is a wasteful number, since it uses less digits than its factorization.

667554661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4956.

The product of its digits is 907200, while the sum is 46.

The square root of 667554661 is about 25837.0791886390. The cubic root of 667554661 is about 873.9681599029.

The spelling of 667554661 in words is "six hundred sixty-seven million, five hundred fifty-four thousand, six hundred sixty-one".