661650061161 has 8 divisors (see below), whose sum is σ = 934094204064. Its totient is φ = 415152979520.

The previous prime is 661650061157. The next prime is 661650061169. The reversal of 661650061161 is 161160056166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 661650061161 - 2² = 661650061157 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (661650061169) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6486765255 + ... + 6486765356.

It is an arithmetic number, because the mean of its divisors is an integer number (116761775508).

Almost surely, 2^661650061161 is an apocalyptic number.

It is an amenable number.

661650061161 is a deficient number, since it is larger than the sum of its proper divisors (272444142903).

661650061161 is a wasteful number, since it uses less digits than its factorization.

661650061161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12973530631.

The product of its (nonzero) digits is 38880, while the sum is 39.

The spelling of 661650061161 in words is "six hundred sixty-one billion, six hundred fifty million, sixty-one thousand, one hundred sixty-one".