1999377844571 has 2 divisors, whose sum is σ = 1999377844572. Its totient is φ = 1999377844570.

The previous prime is 1999377844559. The next prime is 1999377844573. The reversal of 1999377844571 is 1754487739991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1999377844571 - 2²⁶ = 1999310735707 is a prime.

It is a super-2 number, since 2×1999377844571² (a number of 25 digits) contains 22 as substring.

Together with 1999377844573, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1999377844573) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999688922285 + 999688922286.

It is an arithmetic number, because the mean of its divisors is an integer number (999688922286).

Almost surely, 2^{1999377844571} is an apocalyptic number.

1999377844571 is a deficient number, since it is larger than the sum of its proper divisors (1).

1999377844571 is an equidigital number, since it uses as much as digits as its factorization.

1999377844571 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 480090240, while the sum is 74.

The spelling of 1999377844571 in words is "one trillion, nine hundred ninety-nine billion, three hundred seventy-seven million, eight hundred forty-four thousand, five hundred seventy-one".