168991784973 has 80 divisors (see below), whose sum is σ = 288674350272. Its totient is φ = 97596576000.

The previous prime is 168991784963. The next prime is 168991785019. The reversal of 168991784973 is 379487199861.

168991784973 is a `hidden beast` number, since 1 + 68 + 9 + 9 + 1 + 78 + 497 + 3 = 666.

It is not a de Polignac number, because 168991784973 - 2¹⁰ = 168991783949 is a prime.

It is a super-2 number, since 2×168991784973² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168991784963) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 1517043 + ... + 1624623.

Almost surely, 2^168991784973 is an apocalyptic number.

It is an amenable number.

168991784973 is a deficient number, since it is larger than the sum of its proper divisors (119682565299).

168991784973 is a wasteful number, since it uses less digits than its factorization.

168991784973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107688 (or 107679 counting only the distinct ones).

The product of its digits is 164602368, while the sum is 72.

The spelling of 168991784973 in words is "one hundred sixty-eight billion, nine hundred ninety-one million, seven hundred eighty-four thousand, nine hundred seventy-three".