673538661 has 24 divisors (see below), whose sum is σ = 990302040. Its totient is φ = 441040896.

The previous prime is 673538653. The next prime is 673538683. The reversal of 673538661 is 166835376.

It can be written as a sum of positive squares in 4 ways, for example, as 308002500 + 365536161 = 17550^2 + 19119^2 .

It is not a de Polignac number, because 673538661 - 2³ = 673538653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (673538461) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 166855 + ... + 170843.

It is an arithmetic number, because the mean of its divisors is an integer number (41262585).

Almost surely, 2^673538661 is an apocalyptic number.

It is an amenable number.

673538661 is a deficient number, since it is larger than the sum of its proper divisors (316763379).

673538661 is a wasteful number, since it uses less digits than its factorization.

673538661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4325 (or 4322 counting only the distinct ones).

The product of its digits is 544320, while the sum is 45.

The square root of 673538661 is about 25952.6233934067. The cubic root of 673538661 is about 876.5718298396.

The spelling of 673538661 in words is "six hundred seventy-three million, five hundred thirty-eight thousand, six hundred sixty-one".