1138681 has 2 divisors, whose sum is σ = 1138682. Its totient is φ = 1138680.

The previous prime is 1138679. The next prime is 1138703. The reversal of 1138681 is 1868311.

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., 1092025 + 46656 = 1045^2 + 216^2 .

It is a cyclic number.

It is not a de Polignac number, because 1138681 - 2¹ = 1138679 is a prime.

It is a super-2 number, since 2×1138681² = 2593188839522, which contains 22 as substring.

Together with 1138679, it forms a pair of twin primes.

It is equal to p₈₈₅₀₇ and since 1138681 and 88507 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (1133681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 569340 + 569341.

It is an arithmetic number, because the mean of its divisors is an integer number (569341).

2^1138681 is an apocalyptic number.

It is an amenable number.

1138681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1138681 is an equidigital number, since it uses as much as digits as its factorization.

1138681 is an evil number, because the sum of its binary digits is even.

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

The square root of 1138681 is about 1067.0899680908. The cubic root of 1138681 is about 104.4240880888.

The spelling of 1138681 in words is "one million, one hundred thirty-eight thousand, six hundred eighty-one".