166221778347 has 32 divisors (see below), whose sum is σ = 248212546560. Its totient is φ = 109933930080.

The previous prime is 166221778321. The next prime is 166221778351. The reversal of 166221778347 is 743877122661.

166221778347 is a `hidden beast` number, since 1 + 6 + 6 + 221 + 7 + 78 + 347 = 666.

It is not a de Polignac number, because 166221778347 - 2⁸ = 166221778091 is a prime.

It is a super-3 number, since 3×166221778347³ (a number of 35 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 166221778293 and 166221778302.

It is not an unprimeable number, because it can be changed into a prime (166221778147) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16254478 + ... + 16264700.

It is an arithmetic number, because the mean of its divisors is an integer number (7756642080).

Almost surely, 2^166221778347 is an apocalyptic number.

166221778347 is a deficient number, since it is larger than the sum of its proper divisors (81990768213).

166221778347 is a wasteful number, since it uses less digits than its factorization.

166221778347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14960 (or 14954 counting only the distinct ones).

The product of its digits is 4741632, while the sum is 54.

The spelling of 166221778347 in words is "one hundred sixty-six billion, two hundred twenty-one million, seven hundred seventy-eight thousand, three hundred forty-seven".