161287555 has 24 divisors (see below), whose sum is σ = 229115376. Its totient is φ = 108271680.

The previous prime is 161287541. The next prime is 161287573. The reversal of 161287555 is 555782161.

It is a happy number.

It is not a de Polignac number, because 161287555 - 2¹¹ = 161285507 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 2389 + ... + 18118.

It is an arithmetic number, because the mean of its divisors is an integer number (9546474).

Almost surely, 2^161287555 is an apocalyptic number.

161287555 is a deficient number, since it is larger than the sum of its proper divisors (67827821).

161287555 is a wasteful number, since it uses less digits than its factorization.

161287555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20547 (or 20536 counting only the distinct ones).

The product of its digits is 84000, while the sum is 40.

The square root of 161287555 is about 12699.9037397927. The cubic root of 161287555 is about 544.3358686336.

The spelling of 161287555 in words is "one hundred sixty-one million, two hundred eighty-seven thousand, five hundred fifty-five".