1984244651891 has 2 divisors, whose sum is σ = 1984244651892. Its totient is φ = 1984244651890.

The previous prime is 1984244651813. The next prime is 1984244651923. The reversal of 1984244651891 is 1981564424891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1984244651891 - 2²⁶ = 1984177543027 is a prime.

It is not a weakly prime, because it can be changed into another prime (1984244651491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 992122325945 + 992122325946.

It is an arithmetic number, because the mean of its divisors is an integer number (992122325946).

Almost surely, 2^{1984244651891} is an apocalyptic number.

1984244651891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1984244651891 is an equidigital number, since it uses as much as digits as its factorization.

1984244651891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19906560, while the sum is 62.

The spelling of 1984244651891 in words is "one trillion, nine hundred eighty-four billion, two hundred forty-four million, six hundred fifty-one thousand, eight hundred ninety-one".