1663599 has 12 divisors (see below), whose sum is σ = 2580504. Its totient is φ = 950544.

The previous prime is 1663589. The next prime is 1663609. The reversal of 1663599 is 9953661.

It is an interprime number because it is at equal distance from previous prime (1663589) and next prime (1663609).

It is a de Polignac number, because none of the positive numbers 2^k-1663599 is a prime.

1663599 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663549) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5512 + ... + 5805.

It is an arithmetic number, because the mean of its divisors is an integer number (215042).

2^1663599 is an apocalyptic number.

1663599 is a deficient number, since it is larger than the sum of its proper divisors (916905).

1663599 is a wasteful number, since it uses less digits than its factorization.

1663599 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11334 (or 11327 counting only the distinct ones).

The product of its digits is 43740, while the sum is 39.

The square root of 1663599 is about 1289.8057993357. The cubic root of 1663599 is about 118.4903230539.

The spelling of 1663599 in words is "one million, six hundred sixty-three thousand, five hundred ninety-nine".