81426785 has 32 divisors (see below), whose sum is σ = 113218560. Its totient is φ = 55633600.

The previous prime is 81426773. The next prime is 81426791. The reversal of 81426785 is 58762418.

It is not a de Polignac number, because 81426785 - 2²⁰ = 80378209 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 74090 + ... + 75180.

It is an arithmetic number, because the mean of its divisors is an integer number (3538080).

Almost surely, 2^81426785 is an apocalyptic number.

It is an amenable number.

81426785 is a deficient number, since it is larger than the sum of its proper divisors (31791775).

81426785 is a wasteful number, since it uses less digits than its factorization.

81426785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1189.

The product of its digits is 107520, while the sum is 41.

The square root of 81426785 is about 9023.6791277173. The cubic root of 81426785 is about 433.4334545116.

The spelling of 81426785 in words is "eighty-one million, four hundred twenty-six thousand, seven hundred eighty-five".