1661186339 has 4 divisors (see below), whose sum is σ = 1733411856. Its totient is φ = 1588960824.

The previous prime is 1661186327. The next prime is 1661186341. The reversal of 1661186339 is 9336811661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9336811661 = 179 ⋅52160959.

It is a cyclic number.

It is not a de Polignac number, because 1661186339 - 2²⁰ = 1660137763 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1661186339.

It is not an unprimeable number, because it can be changed into a prime (1661186039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36112724 + ... + 36112769.

It is an arithmetic number, because the mean of its divisors is an integer number (433352964).

Almost surely, 2^1661186339 is an apocalyptic number.

1661186339 is a deficient number, since it is larger than the sum of its proper divisors (72225517).

1661186339 is an equidigital number, since it uses as much as digits as its factorization.

1661186339 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72225516.

The product of its digits is 139968, while the sum is 44.

The square root of 1661186339 is about 40757.6537474865. The cubic root of 1661186339 is about 1184.3301451340.

The spelling of 1661186339 in words is "one billion, six hundred sixty-one million, one hundred eighty-six thousand, three hundred thirty-nine".