81567313 has 4 divisors (see below), whose sum is σ = 81794880. Its totient is φ = 81339748.

The previous prime is 81567307. The next prime is 81567329. The reversal of 81567313 is 31376518.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81567313 - 2¹⁷ = 81436241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81567373) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 113245 + ... + 113962.

It is an arithmetic number, because the mean of its divisors is an integer number (20448720).

Almost surely, 2^81567313 is an apocalyptic number.

It is an amenable number.

81567313 is a deficient number, since it is larger than the sum of its proper divisors (227567).

81567313 is a wasteful number, since it uses less digits than its factorization.

81567313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227566.

The product of its digits is 15120, while the sum is 34.

The square root of 81567313 is about 9031.4623954263. The cubic root of 81567313 is about 433.6826539629.

The spelling of 81567313 in words is "eighty-one million, five hundred sixty-seven thousand, three hundred thirteen".