16555515151561 has 2 divisors, whose sum is σ = 16555515151562. Its totient is φ = 16555515151560.

The previous prime is 16555515151543. The next prime is 16555515151573. The reversal of 16555515151561 is 16515151555561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14217273536400 + 2338241615161 = 3770580^2 + 1529131^2 .

It is a cyclic number.

It is not a de Polignac number, because 16555515151561 - 2²⁹ = 16554978280649 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16555515151499 and 16555515151508.

It is not a weakly prime, because it can be changed into another prime (16555515151061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8277757575780 + 8277757575781.

It is an arithmetic number, because the mean of its divisors is an integer number (8277757575781).

Almost surely, 2^{16555515151561} is an apocalyptic number.

It is an amenable number.

16555515151561 is a deficient number, since it is larger than the sum of its proper divisors (1).

16555515151561 is an equidigital number, since it uses as much as digits as its factorization.

16555515151561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2812500, while the sum is 52.

The spelling of 16555515151561 in words is "sixteen trillion, five hundred fifty-five billion, five hundred fifteen million, one hundred fifty-one thousand, five hundred sixty-one".