16505751557 has 2 divisors, whose sum is σ = 16505751558. Its totient is φ = 16505751556.

The previous prime is 16505751553. The next prime is 16505751593. The reversal of 16505751557 is 75515750561.

16505751557 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11888413156 + 4617338401 = 109034^2 + 67951^2 .

It is an emirp because it is prime and its reverse (75515750561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16505751557 - 2² = 16505751553 is a prime.

It is a super-2 number, since 2×16505751557² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16505751553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8252875778 + 8252875779.

It is an arithmetic number, because the mean of its divisors is an integer number (8252875779).

Almost surely, 2^16505751557 is an apocalyptic number.

It is an amenable number.

16505751557 is a deficient number, since it is larger than the sum of its proper divisors (1).

16505751557 is an equidigital number, since it uses as much as digits as its factorization.

16505751557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 918750, while the sum is 47.

The spelling of 16505751557 in words is "sixteen billion, five hundred five million, seven hundred fifty-one thousand, five hundred fifty-seven".