1009781 has 2 divisors, whose sum is σ = 1009782. Its totient is φ = 1009780.

The previous prime is 1009747. The next prime is 1009787. The reversal of 1009781 is 1879001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 707281 + 302500 = 841^2 + 550^2 .

It is a cyclic number.

It is not a de Polignac number, because 1009781 - 2¹⁴ = 993397 is a prime.

It is a super-2 number, since 2×1009781² = 2039315335922, which contains 22 as substring.

It is a Chen prime.

It is equal to p₇₉₂₃₅ and since 1009781 and 79235 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1009781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1009787) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 504890 + 504891.

It is an arithmetic number, because the mean of its divisors is an integer number (504891).

2^1009781 is an apocalyptic number.

It is an amenable number.

1009781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1009781 is an equidigital number, since it uses as much as digits as its factorization.

1009781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 26.

The square root of 1009781 is about 1004.8785996328. The cubic root of 1009781 is about 100.3249760947.

The spelling of 1009781 in words is "one million, nine thousand, seven hundred eighty-one".