3781728 has 60 divisors (see below), whose sum is σ = 11129580. Its totient is φ = 1259712.

The previous prime is 3781727. The next prime is 3781747. The reversal of 3781728 is 8271873.

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

It is a junction number, because it is equal to n+sod(n) for n = 3781692 and 3781701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3781727) 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, 1863 + ... + 3321.

It is an arithmetic number, because the mean of its divisors is an integer number (185493).

Almost surely, 2^3781728 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 3781728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5564790).

3781728 is an abundant number, since it is smaller than the sum of its proper divisors (7347852).

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

3781728 is a wasteful number, since it uses less digits than its factorization.

3781728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1481 (or 1464 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 3781728 is about 1944.6665523940. Note that the first 3 decimals coincide. The cubic root of 3781728 is about 155.7985565553.

The spelling of 3781728 in words is "three million, seven hundred eighty-one thousand, seven hundred twenty-eight".