194571856609 has 9 divisors (see below), whose sum is σ = 210696444819. Its totient is φ = 179599497480.

The previous prime is 194571856579. The next prime is 194571856621. The reversal of 194571856609 is 906658175491.

The square root of 194571856609 is 441103.

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., 28782819025 + 165789037584 = 169655^2 + 407172^2 .

It is not a de Polignac number, because 194571856609 - 2¹³ = 194571848417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (194571856309) 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, 5717374 + ... + 5751304.

It is an arithmetic number, because the mean of its divisors is an integer number (23410716091).

Almost surely, 2^194571856609 is an apocalyptic number.

194571856609 is the 441103-rd square number.

194571856609 is the 220552-nd centered octagonal number.

It is an amenable number.

194571856609 is a deficient number, since it is larger than the sum of its proper divisors (16124588210).

194571856609 is an frugal number, since it uses more digits than its factorization.

194571856609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67888 (or 33944 counting only the distinct ones).

The product of its (nonzero) digits is 16329600, while the sum is 61.

The spelling of 194571856609 in words is "one hundred ninety-four billion, five hundred seventy-one million, eight hundred fifty-six thousand, six hundred nine".