81905459103 has 36 divisors (see below), whose sum is σ = 134851140840. Its totient is φ = 47750534208.

The previous prime is 81905459101. The next prime is 81905459123. The reversal of 81905459103 is 30195450918.

81905459103 is a `hidden beast` number, since 8 + 1 + 9 + 0 + 54 + 591 + 0 + 3 = 666.

It is not a de Polignac number, because 81905459103 - 2¹ = 81905459101 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81905459101) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1388200 + ... + 1445997.

Almost surely, 2^81905459103 is an apocalyptic number.

81905459103 is a deficient number, since it is larger than the sum of its proper divisors (52945681737).

81905459103 is a wasteful number, since it uses less digits than its factorization.

81905459103 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2834248 (or 2834232 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 45.

The spelling of 81905459103 in words is "eighty-one billion, nine hundred five million, four hundred fifty-nine thousand, one hundred three".