2189784521 has 2 divisors, whose sum is σ = 2189784522. Its totient is φ = 2189784520.

The previous prime is 2189784511. The next prime is 2189784533. The reversal of 2189784521 is 1254879812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2084926921 + 104857600 = 45661^2 + 10240^2 .

It is a cyclic number.

It is not a de Polignac number, because 2189784521 - 2²² = 2185590217 is a prime.

It is a super-2 number, since 2×2189784521² = 9590312496822398882, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2189784511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1094892260 + 1094892261.

It is an arithmetic number, because the mean of its divisors is an integer number (1094892261).

Almost surely, 2^2189784521 is an apocalyptic number.

It is an amenable number.

2189784521 is a deficient number, since it is larger than the sum of its proper divisors (1).

2189784521 is an equidigital number, since it uses as much as digits as its factorization.

2189784521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 322560, while the sum is 47.

The square root of 2189784521 is about 46795.1335183478. The cubic root of 2189784521 is about 1298.5752677377.

The spelling of 2189784521 in words is "two billion, one hundred eighty-nine million, seven hundred eighty-four thousand, five hundred twenty-one".