16181643545 has 16 divisors (see below), whose sum is σ = 20897265168. Its totient is φ = 11984087040.

The previous prime is 16181643539. The next prime is 16181643637. The reversal of 16181643545 is 54534618161.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 195328576 + 15986314969 = 13976^2 + 126437^2 .

It is a de Polignac number, because none of the positive numbers 2^k-16181643545 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 16181643496 and 16181643505.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1555244 + ... + 1565613.

It is an arithmetic number, because the mean of its divisors is an integer number (1306079073).

Almost surely, 2^16181643545 is an apocalyptic number.

It is an amenable number.

16181643545 is a deficient number, since it is larger than the sum of its proper divisors (4715621623).

16181643545 is a wasteful number, since it uses less digits than its factorization.

16181643545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3120940.

The product of its digits is 345600, while the sum is 44.

The spelling of 16181643545 in words is "sixteen billion, one hundred eighty-one million, six hundred forty-three thousand, five hundred forty-five".