186841561 has 3 divisors (see below), whose sum is σ = 186855231. Its totient is φ = 186827892.

The previous prime is 186841553. The next prime is 186841607. The reversal of 186841561 is 165148681.

The square root of 186841561 is 13669.

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: 165148681 = 43 ⋅3840667.

It can be written as a sum of positive squares in only one way, i.e., 140873161 + 45968400 = 11869^2 + 6780^2 .

It is not a de Polignac number, because 186841561 - 2³ = 186841553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (186841531) 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, 6835 + ... + 20503.

It is an arithmetic number, because the mean of its divisors is an integer number (62285077).

Almost surely, 2^186841561 is an apocalyptic number.

186841561 is the 13669-th square number.

186841561 is the 6835-th centered octagonal number.

It is an amenable number.

186841561 is a deficient number, since it is larger than the sum of its proper divisors (13670).

186841561 is an frugal number, since it uses more digits than its factorization.

186841561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27338 (or 13669 counting only the distinct ones).

The product of its digits is 46080, while the sum is 40.

The cubic root of 186841561 is about 571.6863581612.

The spelling of 186841561 in words is "one hundred eighty-six million, eight hundred forty-one thousand, five hundred sixty-one".