16551707687641 has 9 divisors (see below), whose sum is σ = 19254060438399. Its totient is φ = 14187153607704.

The previous prime is 16551707687633. The next prime is 16551707687693. The reversal of 16551707687641 is 14678670715561.

The square root of 16551707687641 is 4068379.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 4585615374025 + 11966092313616 = 2141405^2 + 3459204^2 .

It is not a de Polignac number, because 16551707687641 - 2³ = 16551707687633 is a prime.

It is a super-2 number, since 2×16551707687641² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16551707687611) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 28188055 + ... + 28769251.

It is an arithmetic number, because the mean of its divisors is an integer number (2139340048711).

Almost surely, 2^{16551707687641} is an apocalyptic number.

16551707687641 is the 4068379-th square number.

16551707687641 is the 2034190-th centered octagonal number.

It is an amenable number.

16551707687641 is a deficient number, since it is larger than the sum of its proper divisors (2702352750758).

16551707687641 is an frugal number, since it uses more digits than its factorization.

16551707687641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1162408 (or 581204 counting only the distinct ones).

The product of its (nonzero) digits is 59270400, while the sum is 64.

The spelling of 16551707687641 in words is "sixteen trillion, five hundred fifty-one billion, seven hundred seven million, six hundred eighty-seven thousand, six hundred forty-one".