16551588481 has 4 divisors (see below), whose sum is σ = 16552253700. Its totient is φ = 16550923264.

The previous prime is 16551588461. The next prime is 16551588511. The reversal of 16551588481 is 18488515561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15132936256 + 1418652225 = 123016^2 + 37665^2 .

It is a cyclic number.

It is not a de Polignac number, because 16551588481 - 2⁷ = 16551588353 is a prime.

It is a super-2 number, since 2×16551588481² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16551588461) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 293776 + ... + 345553.

It is an arithmetic number, because the mean of its divisors is an integer number (4138063425).

Almost surely, 2^16551588481 is an apocalyptic number.

It is an amenable number.

16551588481 is a deficient number, since it is larger than the sum of its proper divisors (665219).

16551588481 is an equidigital number, since it uses as much as digits as its factorization.

16551588481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665218.

The product of its digits is 1536000, while the sum is 52.

The spelling of 16551588481 in words is "sixteen billion, five hundred fifty-one million, five hundred eighty-eight thousand, four hundred eighty-one".