3931321 has 4 divisors (see below), whose sum is σ = 4102272. Its totient is φ = 3760372.

The previous prime is 3931307. The next prime is 3931331. The reversal of 3931321 is 1231393.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1231393 = 67 ⋅18379.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3931321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3931292 and 3931301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3931331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85441 + ... + 85486.

It is an arithmetic number, because the mean of its divisors is an integer number (1025568).

Almost surely, 2^3931321 is an apocalyptic number.

It is an amenable number.

3931321 is a deficient number, since it is larger than the sum of its proper divisors (170951).

3931321 is a wasteful number, since it uses less digits than its factorization.

3931321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170950.

The product of its digits is 486, while the sum is 22.

The square root of 3931321 is about 1982.7559103430. The cubic root of 3931321 is about 157.8263460910.

The spelling of 3931321 in words is "three million, nine hundred thirty-one thousand, three hundred twenty-one".