16418215521 has 12 divisors (see below), whose sum is σ = 24293620260. Its totient is φ = 10678513920.

The previous prime is 16418215519. The next prime is 16418215537. The reversal of 16418215521 is 12551281461.

16418215521 is a `hidden beast` number, since 1 + 6 + 41 + 82 + 15 + 521 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5518855521 + 10899360000 = 74289^2 + 104400^2 .

It is not a de Polignac number, because 16418215521 - 2¹ = 16418215519 is a prime.

It is a super-3 number, since 3×16418215521³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (16418215591) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22246536 + ... + 22247273.

It is an arithmetic number, because the mean of its divisors is an integer number (2024468355).

Almost surely, 2^16418215521 is an apocalyptic number.

It is an amenable number.

16418215521 is a deficient number, since it is larger than the sum of its proper divisors (7875404739).

16418215521 is a wasteful number, since it uses less digits than its factorization.

16418215521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44493856 (or 44493853 counting only the distinct ones).

The product of its digits is 19200, while the sum is 36.

Adding to 16418215521 its reverse (12551281461), we get a palindrome (28969496982).

The spelling of 16418215521 in words is "sixteen billion, four hundred eighteen million, two hundred fifteen thousand, five hundred twenty-one".