8401681 has 2 divisors, whose sum is σ = 8401682. Its totient is φ = 8401680.

The previous prime is 8401661. The next prime is 8401699. The reversal of 8401681 is 1861048.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4730625 + 3671056 = 2175^2 + 1916^2 .

It is a cyclic number.

It is not a de Polignac number, because 8401681 - 2¹⁷ = 8270609 is a prime.

It is a super-2 number, since 2×8401681² = 141176487251522, which contains 22 as substring.

It is a Chen prime.

8401681 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (8401661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4200840 + 4200841.

It is an arithmetic number, because the mean of its divisors is an integer number (4200841).

Almost surely, 2^8401681 is an apocalyptic number.

It is an amenable number.

8401681 is a deficient number, since it is larger than the sum of its proper divisors (1).

8401681 is an equidigital number, since it uses as much as digits as its factorization.

8401681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 8401681 is about 2898.5653347820. The cubic root of 8401681 is about 203.2928304766.

It can be divided in two parts, 840 and 1681, that multiplied together give a triangular number (1412040 = T₁₆₈₀).

The spelling of 8401681 in words is "eight million, four hundred one thousand, six hundred eighty-one".