1831681 has 2 divisors, whose sum is σ = 1831682. Its totient is φ = 1831680.

The previous prime is 1831679. The next prime is 1831693. The reversal of 1831681 is 1861381.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1540081 + 291600 = 1241^2 + 540^2 .

It is a cyclic number.

It is not a de Polignac number, because 1831681 - 2¹ = 1831679 is a prime.

It is a super-2 number, since 2×1831681² = 6710110571522, which contains 22 as substring.

Together with 1831679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1831601) 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, 915840 + 915841.

It is an arithmetic number, because the mean of its divisors is an integer number (915841).

2^1831681 is an apocalyptic number.

It is an amenable number.

1831681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1831681 is an equidigital number, since it uses as much as digits as its factorization.

1831681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 28.

The square root of 1831681 is about 1353.3960987087. The cubic root of 1831681 is about 122.3535609568.

The spelling of 1831681 in words is "one million, eight hundred thirty-one thousand, six hundred eighty-one".