3894921 has 12 divisors (see below), whose sum is σ = 5957172. Its totient is φ = 2443776.

The previous prime is 3894899. The next prime is 3894923. The reversal of 3894921 is 1294983.

It can be written as a sum of positive squares in 2 ways, for example, as 1299600 + 2595321 = 1140^2 + 1611^2 .

It is not a de Polignac number, because 3894921 - 2⁶ = 3894857 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3894923) 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 11 ways as a sum of consecutive naturals, for example, 12576 + ... + 12881.

It is an arithmetic number, because the mean of its divisors is an integer number (496431).

Almost surely, 2^3894921 is an apocalyptic number.

It is an amenable number.

3894921 is a deficient number, since it is larger than the sum of its proper divisors (2062251).

3894921 is a wasteful number, since it uses less digits than its factorization.

3894921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25480 (or 25477 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 3894921 is about 1973.5554210612. Note that the first 3 decimals coincide. The cubic root of 3894921 is about 157.3377315913.

The spelling of 3894921 in words is "three million, eight hundred ninety-four thousand, nine hundred twenty-one".