1663398 has 48 divisors (see below), whose sum is σ = 4073472. Its totient is φ = 486000.

The previous prime is 1663397. The next prime is 1663457. The reversal of 1663398 is 8933661.

It is a happy number.

1663398 is a `hidden beast` number, since 16 + 633 + 9 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663391) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6003 + ... + 6273.

It is an arithmetic number, because the mean of its divisors is an integer number (84864).

2^1663398 is an apocalyptic number.

1663398 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1663398, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2036736).

1663398 is an abundant number, since it is smaller than the sum of its proper divisors (2410074).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1663398 is a wasteful number, since it uses less digits than its factorization.

1663398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321 (or 318 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 1663398 is about 1289.7278782751. The cubic root of 1663398 is about 118.4855507672.

The spelling of 1663398 in words is "one million, six hundred sixty-three thousand, three hundred ninety-eight".