1139681 has 2 divisors, whose sum is σ = 1139682. Its totient is φ = 1139680.

The previous prime is 1139669. The next prime is 1139683. The reversal of 1139681 is 1869311.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1081600 + 58081 = 1040^2 + 241^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1139681 is a prime.

It is a super-2 number, since 2×1139681² = 2597745563522, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 1139683, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1139683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 569840 + 569841.

It is an arithmetic number, because the mean of its divisors is an integer number (569841).

2^1139681 is an apocalyptic number.

It is an amenable number.

1139681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1139681 is an equidigital number, since it uses as much as digits as its factorization.

1139681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 29.

The square root of 1139681 is about 1067.5584293143. The cubic root of 1139681 is about 104.4546478723.

The spelling of 1139681 in words is "one million, one hundred thirty-nine thousand, six hundred eighty-one".