661640585046166 has 12 divisors (see below), whose sum is σ = 1090886749725276. Its totient is φ = 300745720475420.

The previous prime is 661640585046163. The next prime is 661640585046169.

661640585046166 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (661640585046163) and next prime (661640585046169).

It is a junction number, because it is equal to n+sod(n) for n = 661640585046098 and 661640585046107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661640585046163) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1367026001920 + ... + 1367026002403.

It is an arithmetic number, because the mean of its divisors is an integer number (90907229143773).

Almost surely, 2^{661640585046166} is an apocalyptic number.

661640585046166 is a deficient number, since it is larger than the sum of its proper divisors (429246164679110).

661640585046166 is a wasteful number, since it uses less digits than its factorization.

661640585046166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2734052004347 (or 2734052004336 counting only the distinct ones).

The product of its (nonzero) digits is 149299200, while the sum is 64.

The spelling of 661640585046166 in words is "six hundred sixty-one trillion, six hundred forty billion, five hundred eighty-five million, forty-six thousand, one hundred sixty-six".