181996784537 has 2 divisors, whose sum is σ = 181996784538. Its totient is φ = 181996784536.

The previous prime is 181996784513. The next prime is 181996784687. The reversal of 181996784537 is 735487699181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 142054363801 + 39942420736 = 376901^2 + 199856^2 .

It is a cyclic number.

It is not a de Polignac number, because 181996784537 - 2³⁴ = 164816915353 is a prime.

It is not a weakly prime, because it can be changed into another prime (181996781537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90998392268 + 90998392269.

It is an arithmetic number, because the mean of its divisors is an integer number (90998392269).

Almost surely, 2^181996784537 is an apocalyptic number.

It is an amenable number.

181996784537 is a deficient number, since it is larger than the sum of its proper divisors (1).

181996784537 is an equidigital number, since it uses as much as digits as its factorization.

181996784537 is an evil number, because the sum of its binary digits is even.

The product of its digits is 91445760, while the sum is 68.

The spelling of 181996784537 in words is "one hundred eighty-one billion, nine hundred ninety-six million, seven hundred eighty-four thousand, five hundred thirty-seven".