161800001618 has 16 divisors (see below), whose sum is σ = 257294163960. Its totient is φ = 76047046656.

The previous prime is 161800001609. The next prime is 161800001677. The reversal of 161800001618 is 816100008161.

It can be written as a sum of positive squares in 4 ways, for example, as 159525951649 + 2274049969 = 399407^2 + 47687^2 .

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 7 ways as a sum of consecutive naturals, for example, 2913671 + ... + 2968682.

Almost surely, 2^161800001618 is an apocalyptic number.

161800001618 is a deficient number, since it is larger than the sum of its proper divisors (95494162342).

161800001618 is a wasteful number, since it uses less digits than its factorization.

161800001618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5883181.

The product of its (nonzero) digits is 2304, while the sum is 32.

Adding to 161800001618 its reverse (816100008161), we get a palindrome (977900009779).

It can be divided in two parts, 16180000 and 1618, that multiplied together give a square (26179240000 = 161800²).

The spelling of 161800001618 in words is "one hundred sixty-one billion, eight hundred million, one thousand, six hundred eighteen".