1998457 has 2 divisors, whose sum is σ = 1998458. Its totient is φ = 1998456.

The previous prime is 1998449. The next prime is 1998473. The reversal of 1998457 is 7548991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1666681 + 331776 = 1291^2 + 576^2 .

It is a cyclic number.

It is not a de Polignac number, because 1998457 - 2³ = 1998449 is a prime.

It is not a weakly prime, because it can be changed into another prime (1998427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 999228 + 999229.

It is an arithmetic number, because the mean of its divisors is an integer number (999229).

2^1998457 is an apocalyptic number.

It is an amenable number.

1998457 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998457 is an equidigital number, since it uses as much as digits as its factorization.

1998457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 43.

The square root of 1998457 is about 1413.6679242311. The cubic root of 1998457 is about 125.9596956838.

The spelling of 1998457 in words is "one million, nine hundred ninety-eight thousand, four hundred fifty-seven".