1663400 has 24 divisors (see below), whose sum is σ = 3867870. Its totient is φ = 665280.

The previous prime is 1663397. The next prime is 1663457. The reversal of 1663400 is 43661.

It can be written as a sum of positive squares in 3 ways, for example, as 1592644 + 70756 = 1262^2 + 266^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3959 + ... + 4358.

2^1663400 is an apocalyptic number.

1663400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1663400 is an abundant number, since it is smaller than the sum of its proper divisors (2204470).

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

1663400 is a wasteful number, since it uses less digits than its factorization.

1663400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8333 (or 8324 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 1663400 is about 1289.7286536322. The cubic root of 1663400 is about 118.4855982545.

The spelling of 1663400 in words is "one million, six hundred sixty-three thousand, four hundred".