186666338401 has 9 divisors (see below), whose sum is σ = 191864157849. Its totient is φ = 181605748464.

The previous prime is 186666338393. The next prime is 186666338423. The reversal of 186666338401 is 104833666681.

The square root of 186666338401 is 432049.

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

It can be written as a sum of positive squares in 4 ways, for example, as 105236008801 + 81430329600 = 324401^2 + 285360^2 .

It is not a de Polignac number, because 186666338401 - 2³ = 186666338393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (186666338461) 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, 15979975 + ... + 15991651.

It is an arithmetic number, because the mean of its divisors is an integer number (21318239761).

Almost surely, 2^186666338401 is an apocalyptic number.

186666338401 is the 432049-th square number.

186666338401 is the 216025-th centered octagonal number.

It is an amenable number.

186666338401 is a deficient number, since it is larger than the sum of its proper divisors (5197819448).

186666338401 is an frugal number, since it uses more digits than its factorization.

186666338401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23428 (or 11714 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 52.

The spelling of 186666338401 in words is "one hundred eighty-six billion, six hundred sixty-six million, three hundred thirty-eight thousand, four hundred one".