2166404643242 has 12 divisors (see below), whose sum is σ = 3780155040930. Its totient is φ = 928459132776.

The previous prime is 2166404643197. The next prime is 2166404643251. The reversal of 2166404643242 is 2423464046612.

It can be written as a sum of positive squares in only one way, i.e., 1455302036881 + 711102606361 = 1206359^2 + 843269^2 .

It is a junction number, because it is equal to n+sod(n) for n = 2166404643193 and 2166404643202.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11053084817 + ... + 11053085012.

Almost surely, 2^{2166404643242} is an apocalyptic number.

2166404643242 is a deficient number, since it is larger than the sum of its proper divisors (1613750397688).

2166404643242 is a wasteful number, since it uses less digits than its factorization.

2166404643242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22106169845 (or 22106169838 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 44.

Adding to 2166404643242 its reverse (2423464046612), we get a palindrome (4589868689854).

The spelling of 2166404643242 in words is "two trillion, one hundred sixty-six billion, four hundred four million, six hundred forty-three thousand, two hundred forty-two".