81800734919 has 2 divisors, whose sum is σ = 81800734920. Its totient is φ = 81800734918.

The previous prime is 81800734907. The next prime is 81800734927. The reversal of 81800734919 is 91943700818.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81800734919 - 2¹⁶ = 81800669383 is a prime.

It is a super-2 number, since 2×81800734919² (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 (81800734969) 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, 40900367459 + 40900367460.

It is an arithmetic number, because the mean of its divisors is an integer number (40900367460).

Almost surely, 2^81800734919 is an apocalyptic number.

81800734919 is a deficient number, since it is larger than the sum of its proper divisors (1).

81800734919 is an equidigital number, since it uses as much as digits as its factorization.

81800734919 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 435456, while the sum is 50.

The spelling of 81800734919 in words is "eighty-one billion, eight hundred million, seven hundred thirty-four thousand, nine hundred nineteen".