809782214641 has 9 divisors (see below), whose sum is σ = 819064130763. Its totient is φ = 800604348720.

The previous prime is 809782214639. The next prime is 809782214687. The reversal of 809782214641 is 146412287908.

The square root of 809782214641 is 899879.

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., 155495360241 + 654286854400 = 394329^2 + 808880^2 .

It is not a de Polignac number, because 809782214641 - 2¹ = 809782214639 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (809782214041) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 80084176 + ... + 80094286.

Almost surely, 2^809782214641 is an apocalyptic number.

809782214641 is the 899879-th square number.

809782214641 is the 449940-th centered octagonal number.

It is an amenable number.

809782214641 is a deficient number, since it is larger than the sum of its proper divisors (9281916122).

809782214641 is an frugal number, since it uses more digits than its factorization.

809782214641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20400 (or 10200 counting only the distinct ones).

The product of its (nonzero) digits is 1548288, while the sum is 52.

The spelling of 809782214641 in words is "eight hundred nine billion, seven hundred eighty-two million, two hundred fourteen thousand, six hundred forty-one".