1638625 has 8 divisors (see below), whose sum is σ = 2045160. Its totient is φ = 1310800.

The previous prime is 1638599. The next prime is 1638641. The reversal of 1638625 is 5268361.

It can be written as a sum of positive squares in 4 ways, for example, as 118336 + 1520289 = 344^2 + 1233^2 .

It is not a de Polignac number, because 1638625 - 2¹¹ = 1636577 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6430 + ... + 6679.

It is an arithmetic number, because the mean of its divisors is an integer number (255645).

2^1638625 is an apocalyptic number.

It is an amenable number.

1638625 is a deficient number, since it is larger than the sum of its proper divisors (406535).

1638625 is an equidigital number, since it uses as much as digits as its factorization.

1638625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13124 (or 13114 counting only the distinct ones).

The product of its digits is 8640, while the sum is 31.

The square root of 1638625 is about 1280.0878876077. The cubic root of 1638625 is about 117.8944042400.

The spelling of 1638625 in words is "one million, six hundred thirty-eight thousand, six hundred twenty-five".