661706396193 has 4 divisors (see below), whose sum is σ = 882275194928. Its totient is φ = 441137597460.

The previous prime is 661706396191. The next prime is 661706396201. The reversal of 661706396193 is 391693607166.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 661706396193 - 2¹ = 661706396191 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661706396191) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 110284399363 + ... + 110284399368.

It is an arithmetic number, because the mean of its divisors is an integer number (220568798732).

Almost surely, 2^661706396193 is an apocalyptic number.

It is an amenable number.

661706396193 is a deficient number, since it is larger than the sum of its proper divisors (220568798735).

661706396193 is a wasteful number, since it uses less digits than its factorization.

661706396193 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220568798734.

The product of its (nonzero) digits is 6613488, while the sum is 57.

The spelling of 661706396193 in words is "six hundred sixty-one billion, seven hundred six million, three hundred ninety-six thousand, one hundred ninety-three".