3937721 has 2 divisors, whose sum is σ = 3937722. Its totient is φ = 3937720.

The previous prime is 3937709. The next prime is 3937751. The reversal of 3937721 is 1277393.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2805625 + 1132096 = 1675^2 + 1064^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3937721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3937751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1968860 + 1968861.

It is an arithmetic number, because the mean of its divisors is an integer number (1968861).

Almost surely, 2^3937721 is an apocalyptic number.

It is an amenable number.

3937721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3937721 is an equidigital number, since it uses as much as digits as its factorization.

3937721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7938, while the sum is 32.

The square root of 3937721 is about 1984.3691692828. The cubic root of 3937721 is about 157.9119442046.

The spelling of 3937721 in words is "three million, nine hundred thirty-seven thousand, seven hundred twenty-one".