985771609 has 3 divisors (see below), whose sum is σ = 985803007. Its totient is φ = 985740212.

The previous prime is 985771607. The next prime is 985771637. The reversal of 985771609 is 906177589.

It is a happy number.

The square root of 985771609 is 31397.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 906177589 = 97 ⋅9342037.

It can be written as a sum of positive squares in only one way, i.e., 417998025 + 567773584 = 20445^2 + 23828^2 .

It is not a de Polignac number, because 985771609 - 2¹ = 985771607 is a prime.

It is a super-2 number, since 2×985771609² = 1943491330220897762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (985771601) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 15699 + ... + 47095.

Almost surely, 2^985771609 is an apocalyptic number.

985771609 is the 31397-th square number.

985771609 is the 15699-th centered octagonal number.

It is an amenable number.

985771609 is a deficient number, since it is larger than the sum of its proper divisors (31398).

985771609 is an frugal number, since it uses more digits than its factorization.

985771609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62794 (or 31397 counting only the distinct ones).

The product of its (nonzero) digits is 952560, while the sum is 52.

The cubic root of 985771609 is about 995.2345293638.

The spelling of 985771609 in words is "nine hundred eighty-five million, seven hundred seventy-one thousand, six hundred nine".