1998786371 has 2 divisors, whose sum is σ = 1998786372. Its totient is φ = 1998786370.

The previous prime is 1998786353. The next prime is 1998786431. The reversal of 1998786371 is 1736878991.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1998786371 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1998786371.

It is not a weakly prime, because it can be changed into another prime (1998782371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999393185 + 999393186.

It is an arithmetic number, because the mean of its divisors is an integer number (999393186).

Almost surely, 2^1998786371 is an apocalyptic number.

1998786371 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998786371 is an equidigital number, since it uses as much as digits as its factorization.

1998786371 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4572288, while the sum is 59.

The square root of 1998786371 is about 44707.7887062199. The cubic root of 1998786371 is about 1259.6661522087. Note that the first 3 decimals are identical.

The spelling of 1998786371 in words is "one billion, nine hundred ninety-eight million, seven hundred eighty-six thousand, three hundred seventy-one".