1998947 has 2 divisors, whose sum is σ = 1998948. Its totient is φ = 1998946.

The previous prime is 1998943. The next prime is 1998949. The reversal of 1998947 is 7498991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1998947 - 2² = 1998943 is a prime.

Together with 1998949, 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 (1998943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999473 + 999474.

It is an arithmetic number, because the mean of its divisors is an integer number (999474).

2^1998947 is an apocalyptic number.

1998947 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998947 is an equidigital number, since it uses as much as digits as its factorization.

1998947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 47.

The square root of 1998947 is about 1413.8412216370. The cubic root of 1998947 is about 125.9699894933.

The spelling of 1998947 in words is "one million, nine hundred ninety-eight thousand, nine hundred forty-seven".