81335507 has 4 divisors (see below), whose sum is σ = 88729656. Its totient is φ = 73941360.

The previous prime is 81335483. The next prime is 81335539. The reversal of 81335507 is 70553318.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81335507 - 2⁸ = 81335251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81335557) 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 3 ways as a sum of consecutive naturals, for example, 3697058 + ... + 3697079.

It is an arithmetic number, because the mean of its divisors is an integer number (22182414).

Almost surely, 2^81335507 is an apocalyptic number.

81335507 is a deficient number, since it is larger than the sum of its proper divisors (7394149).

81335507 is a wasteful number, since it uses less digits than its factorization.

81335507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7394148.

The product of its (nonzero) digits is 12600, while the sum is 32.

The square root of 81335507 is about 9018.6200163883. The cubic root of 81335507 is about 433.2714368529.

The spelling of 81335507 in words is "eighty-one million, three hundred thirty-five thousand, five hundred seven".