2185555521 has 16 divisors (see below), whose sum is σ = 3009363968. Its totient is φ = 1409432400.

The previous prime is 2185555517. The next prime is 2185555529. The reversal of 2185555521 is 1255555812.

It is not a de Polignac number, because 2185555521 - 2² = 2185555517 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2185555521.

It is not an unprimeable number, because it can be changed into a prime (2185555529) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 340080 + ... + 346446.

It is an arithmetic number, because the mean of its divisors is an integer number (188085248).

Almost surely, 2^2185555521 is an apocalyptic number.

It is an amenable number.

2185555521 is a deficient number, since it is larger than the sum of its proper divisors (823808447).

2185555521 is a wasteful number, since it uses less digits than its factorization.

2185555521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10092.

The product of its digits is 100000, while the sum is 39.

The square root of 2185555521 is about 46749.9253582292. The cubic root of 2185555521 is about 1297.7387754101.

The spelling of 2185555521 in words is "two billion, one hundred eighty-five million, five hundred fifty-five thousand, five hundred twenty-one".