1998856742431 has 2 divisors, whose sum is σ = 1998856742432. Its totient is φ = 1998856742430.

The previous prime is 1998856742387. The next prime is 1998856742453. The reversal of 1998856742431 is 1342476588991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1998856742431 - 2¹¹ = 1998856740383 is a prime.

It is a super-2 number, since 2×1998856742431² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1998856742461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999428371215 + 999428371216.

It is an arithmetic number, because the mean of its divisors is an integer number (999428371216).

Almost surely, 2^{1998856742431} is an apocalyptic number.

1998856742431 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998856742431 is an equidigital number, since it uses as much as digits as its factorization.

1998856742431 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 104509440, while the sum is 67.

The spelling of 1998856742431 in words is "one trillion, nine hundred ninety-eight billion, eight hundred fifty-six million, seven hundred forty-two thousand, four hundred thirty-one".