81182913 has 8 divisors (see below), whose sum is σ = 123707328. Its totient is φ = 46390224.

The previous prime is 81182903. The next prime is 81182923. The reversal of 81182913 is 31928118.

It is an interprime number because it is at equal distance from previous prime (81182903) and next prime (81182923).

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

It is a de Polignac number, because none of the positive numbers 2^k-81182913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81182903) 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 7 ways as a sum of consecutive naturals, for example, 1932906 + ... + 1932947.

It is an arithmetic number, because the mean of its divisors is an integer number (15463416).

Almost surely, 2^81182913 is an apocalyptic number.

It is an amenable number.

81182913 is a deficient number, since it is larger than the sum of its proper divisors (42524415).

81182913 is a wasteful number, since it uses less digits than its factorization.

81182913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3865863.

The product of its digits is 3456, while the sum is 33.

The square root of 81182913 is about 9010.1561029762. The cubic root of 81182913 is about 433.0003129070. Note that the first 3 decimals are identical.

The spelling of 81182913 in words is "eighty-one million, one hundred eighty-two thousand, nine hundred thirteen".