2018221521 has 16 divisors (see below), whose sum is σ = 2850408000. Its totient is φ = 1265822208.

The previous prime is 2018221519. The next prime is 2018221559. The reversal of 2018221521 is 1251228102.

It is not a de Polignac number, because 2018221521 - 2¹ = 2018221519 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 2018221491 and 2018221500.

It is not an unprimeable number, because it can be changed into a prime (2018221511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 149010 + ... + 161988.

It is an arithmetic number, because the mean of its divisors is an integer number (178150500).

Almost surely, 2^2018221521 is an apocalyptic number.

It is an amenable number.

2018221521 is a deficient number, since it is larger than the sum of its proper divisors (832186479).

2018221521 is a wasteful number, since it uses less digits than its factorization.

2018221521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16048.

The product of its (nonzero) digits is 640, while the sum is 24.

The square root of 2018221521 is about 44924.6204324533. The cubic root of 2018221521 is about 1263.7357678946.

Adding to 2018221521 its reverse (1251228102), we get a palindrome (3269449623).

The spelling of 2018221521 in words is "two billion, eighteen million, two hundred twenty-one thousand, five hundred twenty-one".