81930311 has 8 divisors (see below), whose sum is σ = 82878000. Its totient is φ = 80986752.

The previous prime is 81930283. The next prime is 81930319. The reversal of 81930311 is 11303918.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81930311 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81930319) 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, 55661 + ... + 57113.

It is an arithmetic number, because the mean of its divisors is an integer number (10359750).

Almost surely, 2^81930311 is an apocalyptic number.

81930311 is a deficient number, since it is larger than the sum of its proper divisors (947689).

81930311 is a wasteful number, since it uses less digits than its factorization.

81930311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2065.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 81930311 is about 9051.5363889232. The cubic root of 81930311 is about 434.3250394793.

The spelling of 81930311 in words is "eighty-one million, nine hundred thirty thousand, three hundred eleven".