2161440164 has 12 divisors (see below), whose sum is σ = 4073483484. Its totient is φ = 997587744.

The previous prime is 2161440121. The next prime is 2161440179. The reversal of 2161440164 is 4610441612.

It can be written as a sum of positive squares in 2 ways, for example, as 900480064 + 1260960100 = 30008^2 + 35510^2 .

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, 20783027 + ... + 20783130.

It is an arithmetic number, because the mean of its divisors is an integer number (339456957).

Almost surely, 2^2161440164 is an apocalyptic number.

It is an amenable number.

2161440164 is a deficient number, since it is larger than the sum of its proper divisors (1912043320).

2161440164 is a wasteful number, since it uses less digits than its factorization.

2161440164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41566174 (or 41566172 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 2161440164 is about 46491.2912705165. The cubic root of 2161440164 is about 1292.9480408673.

Adding to 2161440164 its reverse (4610441612), we get a palindrome (6771881776).

The spelling of 2161440164 in words is "two billion, one hundred sixty-one million, four hundred forty thousand, one hundred sixty-four".