42004121666 has 16 divisors (see below), whose sum is σ = 67858639800. Its totient is φ = 19384852608.

The previous prime is 42004121659. The next prime is 42004121711. The reversal of 42004121666 is 66612140024.

It can be written as a sum of positive squares in 4 ways, for example, as 40795516441 + 1208605225 = 201979^2 + 34765^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 270590 + ... + 396518.

Almost surely, 2^42004121666 is an apocalyptic number.

42004121666 is a deficient number, since it is larger than the sum of its proper divisors (25854518134).

42004121666 is a wasteful number, since it uses less digits than its factorization.

42004121666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138773.

The product of its (nonzero) digits is 13824, while the sum is 32.

The spelling of 42004121666 in words is "forty-two billion, four million, one hundred twenty-one thousand, six hundred sixty-six".