16399106275561 has 9 divisors (see below), whose sum is σ = 16545977101381. Its totient is φ = 16253527888192.

The previous prime is 16399106275543. The next prime is 16399106275681. The reversal of 16399106275561 is 16557260199361.

The square root of 16399106275561 is 4049581.

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

It can be written as a sum of positive squares in 4 ways, for example, as 9576666755161 + 6822439520400 = 3094619^2 + 2611980^2 .

It is not a de Polignac number, because 16399106275561 - 2²¹ = 16399104178409 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16399106275561.

It is not an unprimeable number, because it can be changed into a prime (16399106275061) 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, 457584735 + ... + 457620571.

Almost surely, 2^{16399106275561} is an apocalyptic number.

16399106275561 is the 4049581-st square number.

16399106275561 is the 2024791-st centered octagonal number.

It is an amenable number.

16399106275561 is a deficient number, since it is larger than the sum of its proper divisors (146870825820).

16399106275561 is an frugal number, since it uses more digits than its factorization.

16399106275561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71900 (or 35950 counting only the distinct ones).

The product of its (nonzero) digits is 18370800, while the sum is 61.

The spelling of 16399106275561 in words is "sixteen trillion, three hundred ninety-nine billion, one hundred six million, two hundred seventy-five thousand, five hundred sixty-one".