1031981 has 2 divisors, whose sum is σ = 1031982. Its totient is φ = 1031980.

The previous prime is 1031923. The next prime is 1031999. The reversal of 1031981 is 1891301.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1020100 + 11881 = 1010^2 + 109^2 .

It is a cyclic number.

It is not a de Polignac number, because 1031981 - 2¹⁰ = 1030957 is a prime.

It is a super-2 number, since 2×1031981² = 2129969568722, which contains 22 as substring.

It is a Chen prime.

It is equal to p₈₀₈₃₄ and since 1031981 and 80834 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1031911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 515990 + 515991.

It is an arithmetic number, because the mean of its divisors is an integer number (515991).

2^1031981 is an apocalyptic number.

It is an amenable number.

1031981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1031981 is an equidigital number, since it uses as much as digits as its factorization.

1031981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 23.

The square root of 1031981 is about 1015.8646563396. The cubic root of 1031981 is about 101.0548667678.

The spelling of 1031981 in words is "one million, thirty-one thousand, nine hundred eighty-one".