661161066497 has 8 divisors (see below), whose sum is σ = 703963807200. Its totient is φ = 618792871744.

The previous prime is 661161066443. The next prime is 661161066499. The reversal of 661161066497 is 794660161166.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661161066497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661161066499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 108633347 + ... + 108639432.

It is an arithmetic number, because the mean of its divisors is an integer number (87995475900).

Almost surely, 2^661161066497 is an apocalyptic number.

It is an amenable number.

661161066497 is a deficient number, since it is larger than the sum of its proper divisors (42802740703).

661161066497 is a wasteful number, since it uses less digits than its factorization.

661161066497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217272975.

The product of its (nonzero) digits is 1959552, while the sum is 53.

The spelling of 661161066497 in words is "six hundred sixty-one billion, one hundred sixty-one million, sixty-six thousand, four hundred ninety-seven".