81314569 has 12 divisors (see below), whose sum is σ = 95288724. Its totient is φ = 69183744.

The previous prime is 81314551. The next prime is 81314573. The reversal of 81314569 is 96541318.

It can be written as a sum of positive squares in 2 ways, for example, as 36156169 + 45158400 = 6013^2 + 6720^2 .

It is not a de Polignac number, because 81314569 - 2²¹ = 79217417 is a prime.

It is a super-2 number, since 2×81314569² = 13224118263311522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81314549) 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 11 ways as a sum of consecutive naturals, for example, 657 + ... + 12769.

It is an arithmetic number, because the mean of its divisors is an integer number (7940727).

Almost surely, 2^81314569 is an apocalyptic number.

It is an amenable number.

81314569 is a deficient number, since it is larger than the sum of its proper divisors (13974155).

81314569 is a wasteful number, since it uses less digits than its factorization.

81314569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12264 (or 12257 counting only the distinct ones).

The product of its digits is 25920, while the sum is 37.

The square root of 81314569 is about 9017.4591210607. The cubic root of 81314569 is about 433.2342549945.

The spelling of 81314569 in words is "eighty-one million, three hundred fourteen thousand, five hundred sixty-nine".