161566567 has 4 divisors (see below), whose sum is σ = 161601856. Its totient is φ = 161531280.

The previous prime is 161566553. The next prime is 161566577. The reversal of 161566567 is 765665161.

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 161566567 - 2¹¹ = 161564519 is a prime.

It is a super-2 number, since 2×161566567² = 52207511144330978, 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 (161566507) 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, 9534 + ... + 20347.

It is an arithmetic number, because the mean of its divisors is an integer number (40400464).

Almost surely, 2^161566567 is an apocalyptic number.

161566567 is a deficient number, since it is larger than the sum of its proper divisors (35289).

161566567 is an equidigital number, since it uses as much as digits as its factorization.

161566567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35288.

The product of its digits is 226800, while the sum is 43.

The square root of 161566567 is about 12710.8838009007. The cubic root of 161566567 is about 544.6495707589.

The spelling of 161566567 in words is "one hundred sixty-one million, five hundred sixty-six thousand, five hundred sixty-seven".