81684708037 has 2 divisors, whose sum is σ = 81684708038. Its totient is φ = 81684708036.

The previous prime is 81684708031. The next prime is 81684708143. The reversal of 81684708037 is 73080748618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77017905441 + 4666802596 = 277521^2 + 68314^2 .

It is a cyclic number.

It is not a de Polignac number, because 81684708037 - 2³⁵ = 47324969669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81684708031) 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, 40842354018 + 40842354019.

It is an arithmetic number, because the mean of its divisors is an integer number (40842354019).

Almost surely, 2^81684708037 is an apocalyptic number.

It is an amenable number.

81684708037 is a deficient number, since it is larger than the sum of its proper divisors (1).

81684708037 is an equidigital number, since it uses as much as digits as its factorization.

81684708037 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1806336, while the sum is 52.

The spelling of 81684708037 in words is "eighty-one billion, six hundred eighty-four million, seven hundred eight thousand, thirty-seven".