193195985661 has 24 divisors (see below), whose sum is σ = 319133559680. Its totient is φ = 110326103136.

The previous prime is 193195985621. The next prime is 193195985677. The reversal of 193195985661 is 166589591391.

193195985661 is a `hidden beast` number, since 1 + 9 + 3 + 19 + 59 + 8 + 566 + 1 = 666.

It is not a de Polignac number, because 193195985661 - 2⁷ = 193195985533 is a prime.

It is a hoax number, since the sum of its digits (63) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (193195985621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 896506 + ... + 1090923.

Almost surely, 2^193195985661 is an apocalyptic number.

It is an amenable number.

193195985661 is a deficient number, since it is larger than the sum of its proper divisors (125937574019).

193195985661 is a wasteful number, since it uses less digits than its factorization.

193195985661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1988985 (or 1988982 counting only the distinct ones).

The product of its digits is 15746400, while the sum is 63.

The spelling of 193195985661 in words is "one hundred ninety-three billion, one hundred ninety-five million, nine hundred eighty-five thousand, six hundred sixty-one".