1638460 has 48 divisors (see below), whose sum is σ = 3749760. Its totient is φ = 599040.

The previous prime is 1638431. The next prime is 1638463. The reversal of 1638460 is 648361.

1638460 = 35² + 36² + ... + 170².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638463) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 20701 + ... + 20779.

It is an arithmetic number, because the mean of its divisors is an integer number (78120).

2^1638460 is an apocalyptic number.

1638460 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1638460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1874880).

1638460 is an abundant number, since it is smaller than the sum of its proper divisors (2111300).

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

1638460 is a wasteful number, since it uses less digits than its factorization.

It is an anagram of its base 9 representation: 1638460 = (3066481)₉.

1638460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166 (or 164 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 1638460 is about 1280.0234372854. The cubic root of 1638460 is about 117.8904470137.

Subtracting from 1638460 its reverse (648361), we obtain a palindrome (990099).

The spelling of 1638460 in words is "one million, six hundred thirty-eight thousand, four hundred sixty".