185215567081 has 2 divisors, whose sum is σ = 185215567082. Its totient is φ = 185215567080.

The previous prime is 185215567021. The next prime is 185215567093. The reversal of 185215567081 is 180765512581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 184677327081 + 538240000 = 429741^2 + 23200^2 .

It is a cyclic number.

It is not a de Polignac number, because 185215567081 - 2¹⁷ = 185215436009 is a prime.

It is a super-2 number, since 2×185215567081² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (185215567021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 92607783540 + 92607783541.

It is an arithmetic number, because the mean of its divisors is an integer number (92607783541).

Almost surely, 2^185215567081 is an apocalyptic number.

It is an amenable number.

185215567081 is a deficient number, since it is larger than the sum of its proper divisors (1).

185215567081 is an equidigital number, since it uses as much as digits as its factorization.

185215567081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672000, while the sum is 49.

The spelling of 185215567081 in words is "one hundred eighty-five billion, two hundred fifteen million, five hundred sixty-seven thousand, eighty-one".