81927311 has 4 divisors (see below), whose sum is σ = 85489392. Its totient is φ = 78365232.

The previous prime is 81927299. The next prime is 81927323. The reversal of 81927311 is 11372918.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (81927299) and next prime (81927323).

It is not a de Polignac number, because 81927311 - 2⁶ = 81927247 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 (81927371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1781006 + ... + 1781051.

It is an arithmetic number, because the mean of its divisors is an integer number (21372348).

Almost surely, 2^81927311 is an apocalyptic number.

81927311 is a deficient number, since it is larger than the sum of its proper divisors (3562081).

81927311 is a wasteful number, since it uses less digits than its factorization.

81927311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3562080.

The product of its digits is 3024, while the sum is 32.

The square root of 81927311 is about 9051.3706696831. The cubic root of 81927311 is about 434.3197382625.

The spelling of 81927311 in words is "eighty-one million, nine hundred twenty-seven thousand, three hundred eleven".