166221778349 has 8 divisors (see below), whose sum is σ = 181753580160. Its totient is φ = 150760098400.

The previous prime is 166221778321. The next prime is 166221778351. The reversal of 166221778349 is 943877122661.

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

It is a cyclic number.

It is not a de Polignac number, because 166221778349 - 2³⁶ = 97502301613 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 166221778294 and 166221778303.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166221778049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17525504 + ... + 17534985.

It is an arithmetic number, because the mean of its divisors is an integer number (22719197520).

Almost surely, 2^166221778349 is an apocalyptic number.

It is an amenable number.

166221778349 is a deficient number, since it is larger than the sum of its proper divisors (15531801811).

166221778349 is a wasteful number, since it uses less digits than its factorization.

166221778349 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35060931.

The product of its digits is 6096384, while the sum is 56.

It can be divided in two parts, 16622 and 1778349, that added together give a palindrome (1794971).

The spelling of 166221778349 in words is "one hundred sixty-six billion, two hundred twenty-one million, seven hundred seventy-eight thousand, three hundred forty-nine".