81426513 has 16 divisors (see below), whose sum is σ = 126720000. Its totient is φ = 45538896.

The previous prime is 81426511. The next prime is 81426517. The reversal of 81426513 is 31562418.

It is not a de Polignac number, because 81426513 - 2¹ = 81426511 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81426511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40263 + ... + 42236.

It is an arithmetic number, because the mean of its divisors is an integer number (7920000).

Almost surely, 2^81426513 is an apocalyptic number.

It is an amenable number.

81426513 is a deficient number, since it is larger than the sum of its proper divisors (45293487).

81426513 is a wasteful number, since it uses less digits than its factorization.

81426513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82556.

The product of its digits is 5760, while the sum is 30.

The square root of 81426513 is about 9023.6640562468. The cubic root of 81426513 is about 433.4329718939.

The spelling of 81426513 in words is "eighty-one million, four hundred twenty-six thousand, five hundred thirteen".