160661591 has 4 divisors (see below), whose sum is σ = 161363400. Its totient is φ = 159959784.

The previous prime is 160661581. The next prime is 160661597. The reversal of 160661591 is 195166061.

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 160661591 - 2¹⁰ = 160660567 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (160661597) 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, 350561 + ... + 351018.

It is an arithmetic number, because the mean of its divisors is an integer number (40340850).

Almost surely, 2^160661591 is an apocalyptic number.

160661591 is a deficient number, since it is larger than the sum of its proper divisors (701809).

160661591 is an equidigital number, since it uses as much as digits as its factorization.

160661591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 701808.

The product of its (nonzero) digits is 9720, while the sum is 35.

The square root of 160661591 is about 12675.2353429828. The cubic root of 160661591 is about 543.6307586153.

The spelling of 160661591 in words is "one hundred sixty million, six hundred sixty-one thousand, five hundred ninety-one".