1009781804641 has 9 divisors (see below), whose sum is σ = 1045832740563. Its totient is φ = 974933605800.

The previous prime is 1009781804639. The next prime is 1009781804657. The reversal of 1009781804641 is 1464081879001.

It is a happy number.

The square root of 1009781804641 is 1004879.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 529505084241 + 480276720400 = 727671^2 + 693020^2 .

It is not a de Polignac number, because 1009781804641 - 2¹ = 1009781804639 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1009781804341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 29124166 + ... + 29158816.

Almost surely, 2^{1009781804641} is an apocalyptic number.

1009781804641 is the 1004879-th square number.

1009781804641 is the 502440-th centered octagonal number.

It is an amenable number.

1009781804641 is a deficient number, since it is larger than the sum of its proper divisors (36050935922).

1009781804641 is an frugal number, since it uses more digits than its factorization.

1009781804641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69360 (or 34680 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 49.

Multiplying 1009781804641 by its sum of digits (49), we get a square (49479308427409 = 7034153²).

The spelling of 1009781804641 in words is "one trillion, nine billion, seven hundred eighty-one million, eight hundred four thousand, six hundred forty-one".