1638125 has 10 divisors (see below), whose sum is σ = 2047782. Its totient is φ = 1310000.

The previous prime is 1638121. The next prime is 1638127. The reversal of 1638125 is 5218361.

It can be written as a sum of positive squares in 5 ways, for example, as 376996 + 1261129 = 614^2 + 1123^2 .

It is not a de Polignac number, because 1638125 - 2² = 1638121 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1638094 and 1638103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638121) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 686 + ... + 1935.

2^1638125 is an apocalyptic number.

It is an amenable number.

1638125 is a deficient number, since it is larger than the sum of its proper divisors (409657).

1638125 is an frugal number, since it uses more digits than its factorization.

1638125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2641 (or 2626 counting only the distinct ones).

The product of its digits is 1440, while the sum is 26.

The square root of 1638125 is about 1279.8925736170. The cubic root of 1638125 is about 117.8824118279.

The spelling of 1638125 in words is "one million, six hundred thirty-eight thousand, one hundred twenty-five".