2181473856 has 70 divisors (see below), whose sum is σ = 6466587270. Its totient is φ = 727156224.

The previous prime is 2181473821. The next prime is 2181473863. The reversal of 2181473856 is 6583741812.

2181473856 is a `hidden beast` number, since 21 + 81 + 473 + 85 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1154912256 + 1026561600 = 33984^2 + 32040^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 205221 + ... + 215588.

Almost surely, 2^2181473856 is an apocalyptic number.

It is an amenable number.

2181473856 is an abundant number, since it is smaller than the sum of its proper divisors (4285113414).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2181473856 is an equidigital number, since it uses as much as digits as its factorization.

2181473856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420833 (or 420814 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The square root of 2181473856 is about 46706.2507165797. The cubic root of 2181473856 is about 1296.9304018610.

The spelling of 2181473856 in words is "two billion, one hundred eighty-one million, four hundred seventy-three thousand, eight hundred fifty-six".