1638090 has 32 divisors (see below), whose sum is σ = 4368960. Its totient is φ = 436752.

The previous prime is 1638089. The next prime is 1638097. The reversal of 1638090 is 908361.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an Ulam number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1638097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2764 + ... + 3303.

It is an arithmetic number, because the mean of its divisors is an integer number (136530).

2^1638090 is an apocalyptic number.

1638090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1638090 is an abundant number, since it is smaller than the sum of its proper divisors (2730870).

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

1638090 is a wasteful number, since it uses less digits than its factorization.

1638090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6083 (or 6077 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 1638090 is about 1279.8789005215. The cubic root of 1638090 is about 117.8815722677.

The spelling of 1638090 in words is "one million, six hundred thirty-eight thousand, ninety".