1638936 has 96 divisors (see below), whose sum is σ = 5110560. Its totient is φ = 470016.

The previous prime is 1638929. The next prime is 1638943. The reversal of 1638936 is 6398361.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1638929) and next prime (1638943).

It is a super-2 number, since 2×1638936² = 5372222424192, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 1638936.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15861 + ... + 15963.

It is an arithmetic number, because the mean of its divisors is an integer number (53235).

2^1638936 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1638936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2555280).

1638936 is an abundant number, since it is smaller than the sum of its proper divisors (3471624).

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

1638936 is a wasteful number, since it uses less digits than its factorization.

1638936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145 (or 138 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 1638936 is about 1280.2093578786. The cubic root of 1638936 is about 117.9018622898.

The spelling of 1638936 in words is "one million, six hundred thirty-eight thousand, nine hundred thirty-six".