3825721 has 2 divisors, whose sum is σ = 3825722. Its totient is φ = 3825720.

The previous prime is 3825713. The next prime is 3825739. The reversal of 3825721 is 1275283.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3111696 + 714025 = 1764^2 + 845^2 .

It is an emirp because it is prime and its reverse (1275283) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3825721 - 2³ = 3825713 is a prime.

It is a super-2 number, since 2×3825721² = 29272282339682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 3825721.

It is not a weakly prime, because it can be changed into another prime (3825781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1912860 + 1912861.

It is an arithmetic number, because the mean of its divisors is an integer number (1912861).

Almost surely, 2^3825721 is an apocalyptic number.

It is an amenable number.

3825721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3825721 is an equidigital number, since it uses as much as digits as its factorization.

3825721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3360, while the sum is 28.

The square root of 3825721 is about 1955.9450401277. The cubic root of 3825721 is about 156.4003659701.

The spelling of 3825721 in words is "three million, eight hundred twenty-five thousand, seven hundred twenty-one".