3981651 has 4 divisors (see below), whose sum is σ = 5308872. Its totient is φ = 2654432.

The previous prime is 3981647. The next prime is 3981683. The reversal of 3981651 is 1561893.

3981651 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1561893 = 3 ⋅520631.

It is a cyclic number.

It is not a de Polignac number, because 3981651 - 2² = 3981647 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (3981641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 663606 + ... + 663611.

It is an arithmetic number, because the mean of its divisors is an integer number (1327218).

Almost surely, 2^3981651 is an apocalyptic number.

3981651 is a deficient number, since it is larger than the sum of its proper divisors (1327221).

3981651 is a wasteful number, since it uses less digits than its factorization.

3981651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1327220.

The product of its digits is 6480, while the sum is 33.

The square root of 3981651 is about 1995.4074771835. The cubic root of 3981651 is about 158.4970062493.

The spelling of 3981651 in words is "three million, nine hundred eighty-one thousand, six hundred fifty-one".