161405566 has 8 divisors (see below), whose sum is σ = 276695280. Its totient is φ = 69173808.

The previous prime is 161405539. The next prime is 161405593. The reversal of 161405566 is 665504161.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (161405539) and next prime (161405593).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5764471 + ... + 5764498.

It is an arithmetic number, because the mean of its divisors is an integer number (34586910).

Almost surely, 2^161405566 is an apocalyptic number.

161405566 is a deficient number, since it is larger than the sum of its proper divisors (115289714).

161405566 is a wasteful number, since it uses less digits than its factorization.

161405566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11528978.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 161405566 is about 12704.5490278089. The cubic root of 161405566 is about 544.4685962939.

The spelling of 161405566 in words is "one hundred sixty-one million, four hundred five thousand, five hundred sixty-six".