2181564416 has 24 divisors (see below), whose sum is σ = 4362067710. Its totient is φ = 1090781184.

The previous prime is 2181564409. The next prime is 2181564431. The reversal of 2181564416 is 6144651812.

It can be written as a sum of positive squares in only one way, i.e., 1361314816 + 820249600 = 36896^2 + 28640^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 2181564416.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 530561 + ... + 534656.

Almost surely, 2^2181564416 is an apocalyptic number.

It is an amenable number.

2181564416 is a deficient number, since it is larger than the sum of its proper divisors (2180503294).

2181564416 is an equidigital number, since it uses as much as digits as its factorization.

2181564416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1065239 (or 1065219 counting only the distinct ones).

The product of its digits is 46080, while the sum is 38.

The square root of 2181564416 is about 46707.2201699052. The cubic root of 2181564416 is about 1296.9483481976.

The spelling of 2181564416 in words is "two billion, one hundred eighty-one million, five hundred sixty-four thousand, four hundred sixteen".