3138921 has 6 divisors (see below), whose sum is σ = 4534010. Its totient is φ = 2092608.

The previous prime is 3138917. The next prime is 3138929. The reversal of 3138921 is 1298313.

It can be written as a sum of positive squares in only one way, i.e., 3111696 + 27225 = 1764^2 + 165^2 .

It is not a de Polignac number, because 3138921 - 2² = 3138917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3138929) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 174376 + ... + 174393.

Almost surely, 2^3138921 is an apocalyptic number.

It is an amenable number.

3138921 is a deficient number, since it is larger than the sum of its proper divisors (1395089).

3138921 is a wasteful number, since it uses less digits than its factorization.

3138921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 348775 (or 348772 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 3138921 is about 1771.7000310436. The cubic root of 3138921 is about 146.4176600124.

The spelling of 3138921 in words is "three million, one hundred thirty-eight thousand, nine hundred twenty-one".