661000636 has 12 divisors (see below), whose sum is σ = 1175714680. Its totient is φ = 325082160.

The previous prime is 661000591. The next prime is 661000651. The reversal of 661000636 is 636000166.

661000636 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1354266 + ... + 1354753.

Almost surely, 2^661000636 is an apocalyptic number.

It is an amenable number.

661000636 is a deficient number, since it is larger than the sum of its proper divisors (514714044).

661000636 is a wasteful number, since it uses less digits than its factorization.

661000636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2709084 (or 2709082 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 661000636 is about 25709.9326331284. The cubic root of 661000636 is about 871.0985532549.

The spelling of 661000636 in words is "six hundred sixty-one million, six hundred thirty-six", and thus it is an aban number.