3756821 has 2 divisors, whose sum is σ = 3756822. Its totient is φ = 3756820.

The previous prime is 3756817. The next prime is 3756827. The reversal of 3756821 is 1286573.

It is a happy number.

3756821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2937796 + 819025 = 1714^2 + 905^2 .

It is a cyclic number.

It is not a de Polignac number, because 3756821 - 2² = 3756817 is a prime.

It is a super-2 number, since 2×3756821² = 28227408052082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3756827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1878410 + 1878411.

It is an arithmetic number, because the mean of its divisors is an integer number (1878411).

Almost surely, 2^3756821 is an apocalyptic number.

It is an amenable number.

3756821 is a deficient number, since it is larger than the sum of its proper divisors (1).

3756821 is an equidigital number, since it uses as much as digits as its factorization.

3756821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10080, while the sum is 32.

The square root of 3756821 is about 1938.2520475934. The cubic root of 3756821 is about 155.4557657220.

The spelling of 3756821 in words is "three million, seven hundred fifty-six thousand, eight hundred twenty-one".