661506006637 has 24 divisors (see below), whose sum is σ = 783373219200. Its totient is φ = 547174826688.

The previous prime is 661506006587. The next prime is 661506006643. The reversal of 661506006637 is 736600605166.

It is not a de Polignac number, because 661506006637 - 2³¹ = 659358522989 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 (661506006037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11976039 + ... + 12031147.

It is an arithmetic number, because the mean of its divisors is an integer number (32640550800).

Almost surely, 2^661506006637 is an apocalyptic number.

It is an amenable number.

661506006637 is a deficient number, since it is larger than the sum of its proper divisors (121867212563).

661506006637 is a wasteful number, since it uses less digits than its factorization.

661506006637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57213 (or 57184 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 46.

The spelling of 661506006637 in words is "six hundred sixty-one billion, five hundred six million, six thousand, six hundred thirty-seven".