81265319 has 4 divisors (see below), whose sum is σ = 81623544. Its totient is φ = 80907096.

The previous prime is 81265267. The next prime is 81265333. The reversal of 81265319 is 91356218.

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 81265319 - 2²⁰ = 80216743 is a prime.

It is a super-2 number, since 2×81265319² = 13208104144343522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81265519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 178772 + ... + 179225.

It is an arithmetic number, because the mean of its divisors is an integer number (20405886).

Almost surely, 2^81265319 is an apocalyptic number.

81265319 is a deficient number, since it is larger than the sum of its proper divisors (358225).

81265319 is a wasteful number, since it uses less digits than its factorization.

81265319 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358224.

The product of its digits is 12960, while the sum is 35.

The square root of 81265319 is about 9014.7278938413. The cubic root of 81265319 is about 433.1467713022.

The spelling of 81265319 in words is "eighty-one million, two hundred sixty-five thousand, three hundred nineteen".