3969021 has 16 divisors (see below), whose sum is σ = 6076928. Its totient is φ = 2257200.

The previous prime is 3969019. The next prime is 3969037. The reversal of 3969021 is 1209693.

3969021 = T₃₂₃ + T₃₂₄ + ... + T₃₈₅.

It is not a de Polignac number, because 3969021 - 2¹ = 3969019 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 3969021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3969001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6666 + ... + 7236.

It is an arithmetic number, because the mean of its divisors is an integer number (379808).

Almost surely, 2^3969021 is an apocalyptic number.

It is an amenable number.

3969021 is a deficient number, since it is larger than the sum of its proper divisors (2107907).

3969021 is a wasteful number, since it uses less digits than its factorization.

3969021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 912.

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 3969021 is about 1992.2401963619. The cubic root of 3969021 is about 158.3292418764.

The spelling of 3969021 in words is "three million, nine hundred sixty-nine thousand, twenty-one".