1966168557842 has 4 divisors (see below), whose sum is σ = 2949252836766. Its totient is φ = 983084278920.

The previous prime is 1966168557803. The next prime is 1966168557883. The reversal of 1966168557842 is 2487558616691.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1864401815761 + 101766742081 = 1365431^2 + 319009^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 491542139459 + ... + 491542139462.

Almost surely, 2^{1966168557842} is an apocalyptic number.

1966168557842 is a deficient number, since it is larger than the sum of its proper divisors (983084278924).

1966168557842 is an equidigital number, since it uses as much as digits as its factorization.

1966168557842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 983084278923.

The product of its digits is 174182400, while the sum is 68.

The spelling of 1966168557842 in words is "one trillion, nine hundred sixty-six billion, one hundred sixty-eight million, five hundred fifty-seven thousand, eight hundred forty-two".