81906603093 has 24 divisors (see below), whose sum is σ = 142327265600. Its totient is φ = 44340416064.

The previous prime is 81906603029. The next prime is 81906603133. The reversal of 81906603093 is 39030660918.

It is not a de Polignac number, because 81906603093 - 2⁶ = 81906603029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81906601093) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 34212088 + ... + 34214481.

Almost surely, 2^81906603093 is an apocalyptic number.

It is an amenable number.

81906603093 is a deficient number, since it is larger than the sum of its proper divisors (60420662507).

81906603093 is a wasteful number, since it uses less digits than its factorization.

81906603093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68426601 (or 68426598 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 45.

The spelling of 81906603093 in words is "eighty-one billion, nine hundred six million, six hundred three thousand, ninety-three".