3628781 has 4 divisors (see below), whose sum is σ = 3907932. Its totient is φ = 3349632.

The previous prime is 3628777. The next prime is 3628783. The reversal of 3628781 is 1878263.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 265225 + 3363556 = 515^2 + 1834^2 .

It is not a de Polignac number, because 3628781 - 2² = 3628777 is a prime.

It is a super-2 number, since 2×3628781² = 26336103091922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3628783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 139556 + ... + 139581.

It is an arithmetic number, because the mean of its divisors is an integer number (976983).

Almost surely, 2^3628781 is an apocalyptic number.

It is an amenable number.

3628781 is a deficient number, since it is larger than the sum of its proper divisors (279151).

3628781 is a wasteful number, since it uses less digits than its factorization.

3628781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 279150.

The product of its digits is 16128, while the sum is 35.

The square root of 3628781 is about 1904.9359569287. The cubic root of 3628781 is about 153.6692315991.

The spelling of 3628781 in words is "three million, six hundred twenty-eight thousand, seven hundred eighty-one".