185745609781 has 2 divisors, whose sum is σ = 185745609782. Its totient is φ = 185745609780.

The previous prime is 185745609727. The next prime is 185745609793. The reversal of 185745609781 is 187906547581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 167881950756 + 17863659025 = 409734^2 + 133655^2 .

It is a cyclic number.

It is not a de Polignac number, because 185745609781 - 2⁷ = 185745609653 is a prime.

It is a super-2 number, since 2×185745609781² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (185745609701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 92872804890 + 92872804891.

It is an arithmetic number, because the mean of its divisors is an integer number (92872804891).

Almost surely, 2^185745609781 is an apocalyptic number.

It is an amenable number.

185745609781 is a deficient number, since it is larger than the sum of its proper divisors (1).

185745609781 is an equidigital number, since it uses as much as digits as its factorization.

185745609781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16934400, while the sum is 61.

The spelling of 185745609781 in words is "one hundred eighty-five billion, seven hundred forty-five million, six hundred nine thousand, seven hundred eighty-one".