161685727 has 4 divisors (see below), whose sum is σ = 184783696. Its totient is φ = 138587760.

The previous prime is 161685721. The next prime is 161685737. The reversal of 161685727 is 727586161.

161685727 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 161685727 - 2⁷ = 161685599 is a prime.

It is a super-2 number, since 2×161685727² = 52284548631037058, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161685721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11548974 + ... + 11548987.

It is an arithmetic number, because the mean of its divisors is an integer number (46195924).

Almost surely, 2^161685727 is an apocalyptic number.

161685727 is a deficient number, since it is larger than the sum of its proper divisors (23097969).

161685727 is an equidigital number, since it uses as much as digits as its factorization.

161685727 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23097968.

The product of its digits is 141120, while the sum is 43.

The square root of 161685727 is about 12715.5702585452. The cubic root of 161685727 is about 544.7834361067.

The spelling of 161685727 in words is "one hundred sixty-one million, six hundred eighty-five thousand, seven hundred twenty-seven".