81834973787 has 16 divisors (see below), whose sum is σ = 94165186752. Its totient is φ = 69665650560.

The previous prime is 81834973769. The next prime is 81834973793. The reversal of 81834973787 is 78737943818.

It is a cyclic number.

It is not a de Polignac number, because 81834973787 - 2¹⁰ = 81834972763 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81834973757) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 937613 + ... + 1021169.

It is an arithmetic number, because the mean of its divisors is an integer number (5885324172).

Almost surely, 2^81834973787 is an apocalyptic number.

81834973787 is a deficient number, since it is larger than the sum of its proper divisors (12330212965).

81834973787 is a wasteful number, since it uses less digits than its factorization.

81834973787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84518.

The product of its digits is 56899584, while the sum is 65.

The spelling of 81834973787 in words is "eighty-one billion, eight hundred thirty-four million, nine hundred seventy-three thousand, seven hundred eighty-seven".