3931729 has 2 divisors, whose sum is σ = 3931730. Its totient is φ = 3931728.

The previous prime is 3931721. The next prime is 3931747. The reversal of 3931729 is 9271393.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3323329 + 608400 = 1823^2 + 780^2 .

It is a cyclic number.

It is not a de Polignac number, because 3931729 - 2³ = 3931721 is a prime.

3931729 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 3931694 and 3931703.

It is not a weakly prime, because it can be changed into another prime (3931721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1965864 + 1965865.

It is an arithmetic number, because the mean of its divisors is an integer number (1965865).

Almost surely, 2^3931729 is an apocalyptic number.

It is an amenable number.

3931729 is a deficient number, since it is larger than the sum of its proper divisors (1).

3931729 is an equidigital number, since it uses as much as digits as its factorization.

3931729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10206, while the sum is 34.

The square root of 3931729 is about 1982.8587947708. The cubic root of 3931729 is about 157.8318057419.

The spelling of 3931729 in words is "three million, nine hundred thirty-one thousand, seven hundred twenty-nine".