3981820 has 24 divisors (see below), whose sum is σ = 8404704. Its totient is φ = 1584576.

The previous prime is 3981767. The next prime is 3981821. The reversal of 3981820 is 281893.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3981821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4882 + ... + 5638.

It is an arithmetic number, because the mean of its divisors is an integer number (350196).

Almost surely, 2^3981820 is an apocalyptic number.

It is an amenable number.

3981820 is an abundant number, since it is smaller than the sum of its proper divisors (4422884).

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

3981820 is a wasteful number, since it uses less digits than its factorization.

3981820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1029 (or 1027 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 3981820 is about 1995.4498239745. The cubic root of 3981820 is about 158.4992486704.

The spelling of 3981820 in words is "three million, nine hundred eighty-one thousand, eight hundred twenty".