2181824885 has 4 divisors (see below), whose sum is σ = 2618189868. Its totient is φ = 1745459904.

The previous prime is 2181824867. The next prime is 2181824893. The reversal of 2181824885 is 5884281812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1247361124 + 934463761 = 35318^2 + 30569^2 .

It is a cyclic number.

It is not a de Polignac number, because 2181824885 - 2⁸ = 2181824629 is a prime.

It is a Duffinian number.

It is a congruent number.

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, 218182484 + ... + 218182493.

It is an arithmetic number, because the mean of its divisors is an integer number (654547467).

Almost surely, 2^2181824885 is an apocalyptic number.

It is an amenable number.

2181824885 is a deficient number, since it is larger than the sum of its proper divisors (436364983).

2181824885 is an equidigital number, since it uses as much as digits as its factorization.

2181824885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436364982.

The product of its digits is 327680, while the sum is 47.

The square root of 2181824885 is about 46710.0084029108. The cubic root of 2181824885 is about 1296.9999627474. Note that the first 4 decimals are identical.

The spelling of 2181824885 in words is "two billion, one hundred eighty-one million, eight hundred twenty-four thousand, eight hundred eighty-five".