1071981 has 8 divisors (see below), whose sum is σ = 1588160. Its totient is φ = 714636.

The previous prime is 1071979. The next prime is 1071991. The reversal of 1071981 is 1891701.

It is not a de Polignac number, because 1071981 - 2¹ = 1071979 is a prime.

It is a super-2 number, since 2×1071981² = 2298286528722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 39703 = 1071981 / (1 + 0 + 7 + 1 + 9 + 8 + 1).

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

1071981 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1071911) 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 in 7 ways as a sum of consecutive naturals, for example, 19825 + ... + 19878.

It is an arithmetic number, because the mean of its divisors is an integer number (198520).

2^1071981 is an apocalyptic number.

It is an amenable number.

1071981 is a deficient number, since it is larger than the sum of its proper divisors (516179).

1071981 is an equidigital number, since it uses as much as digits as its factorization.

1071981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39712 (or 39706 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 27.

The square root of 1071981 is about 1035.3651529774. The cubic root of 1071981 is about 102.3439942869.

The spelling of 1071981 in words is "one million, seventy-one thousand, nine hundred eighty-one".