3821681 has 2 divisors, whose sum is σ = 3821682. Its totient is φ = 3821680.

The previous prime is 3821669. The next prime is 3821687. The reversal of 3821681 is 1861283.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3763600 + 58081 = 1940^2 + 241^2 .

It is a cyclic number.

It is not a de Polignac number, because 3821681 - 2¹⁸ = 3559537 is a prime.

It is a super-2 number, since 2×3821681² = 29210491331522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3821687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1910840 + 1910841.

It is an arithmetic number, because the mean of its divisors is an integer number (1910841).

Almost surely, 2^3821681 is an apocalyptic number.

It is an amenable number.

3821681 is a deficient number, since it is larger than the sum of its proper divisors (1).

3821681 is an equidigital number, since it uses as much as digits as its factorization.

3821681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2304, while the sum is 29.

The square root of 3821681 is about 1954.9120184806. The cubic root of 3821681 is about 156.3452931245.

The spelling of 3821681 in words is "three million, eight hundred twenty-one thousand, six hundred eighty-one".