81591035 has 16 divisors (see below), whose sum is σ = 103831200. Its totient is φ = 61376256.

The previous prime is 81591019. The next prime is 81591049. The reversal of 81591035 is 53019518.

It is a cyclic number.

It is not a de Polignac number, because 81591035 - 2⁴ = 81591019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81590992 and 81591010.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9881 + ... + 16149.

It is an arithmetic number, because the mean of its divisors is an integer number (6489450).

Almost surely, 2^81591035 is an apocalyptic number.

81591035 is a deficient number, since it is larger than the sum of its proper divisors (22240165).

81591035 is a wasteful number, since it uses less digits than its factorization.

81591035 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6430.

The product of its (nonzero) digits is 5400, while the sum is 32.

The square root of 81591035 is about 9032.7755977883. The cubic root of 81591035 is about 433.7246921371.

The spelling of 81591035 in words is "eighty-one million, five hundred ninety-one thousand, thirty-five".