2185188421 has 12 divisors (see below), whose sum is σ = 2405011620. Its totient is φ = 1984020480.

The previous prime is 2185188389. The next prime is 2185188479. The reversal of 2185188421 is 1248815812.

It can be written as a sum of positive squares in 6 ways, for example, as 1492972321 + 692216100 = 38639^2 + 26310^2 .

It is not a de Polignac number, because 2185188421 - 2⁵ = 2185188389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2185188121) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 95676 + ... + 116293.

It is an arithmetic number, because the mean of its divisors is an integer number (200417635).

Almost surely, 2^2185188421 is an apocalyptic number.

It is an amenable number.

2185188421 is a deficient number, since it is larger than the sum of its proper divisors (219823199).

2185188421 is a wasteful number, since it uses less digits than its factorization.

2185188421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212056 (or 212043 counting only the distinct ones).

The product of its digits is 40960, while the sum is 40.

The square root of 2185188421 is about 46745.9989838703. The cubic root of 2185188421 is about 1297.6661124836. Note that the first 3 decimals are identical.

The spelling of 2185188421 in words is "two billion, one hundred eighty-five million, one hundred eighty-eight thousand, four hundred twenty-one".