81312427 has 8 divisors (see below), whose sum is σ = 93751776. Its totient is φ = 69078912.

The previous prime is 81312367. The next prime is 81312461. The reversal of 81312427 is 72421318.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81312427 - 2⁷ = 81312299 is a prime.

It is a super-2 number, since 2×81312427² = 13223421569260658, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81312395 and 81312404.

It is not an unprimeable number, because it can be changed into a prime (81312827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50608 + ... + 52189.

It is an arithmetic number, because the mean of its divisors is an integer number (11718972).

Almost surely, 2^81312427 is an apocalyptic number.

81312427 is a deficient number, since it is larger than the sum of its proper divisors (12439349).

81312427 is a wasteful number, since it uses less digits than its factorization.

81312427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102917.

The product of its digits is 2688, while the sum is 28.

The square root of 81312427 is about 9017.3403506799. The cubic root of 81312427 is about 433.2304508549.

The spelling of 81312427 in words is "eighty-one million, three hundred twelve thousand, four hundred twenty-seven".