81523311 has 8 divisors (see below), whose sum is σ = 109149744. Its totient is φ = 54122880.

The previous prime is 81523297. The next prime is 81523369. The reversal of 81523311 is 11332518.

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

It is not a de Polignac number, because 81523311 - 2¹⁵ = 81490543 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81523391) 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, 55656 + ... + 57101.

It is an arithmetic number, because the mean of its divisors is an integer number (13643718).

Almost surely, 2^81523311 is an apocalyptic number.

81523311 is a deficient number, since it is larger than the sum of its proper divisors (27626433).

81523311 is a wasteful number, since it uses less digits than its factorization.

81523311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113001.

The product of its digits is 720, while the sum is 24.

The square root of 81523311 is about 9029.0260272080. The cubic root of 81523311 is about 433.6046556572.

Adding to 81523311 its reverse (11332518), we get a palindrome (92855829).

The spelling of 81523311 in words is "eighty-one million, five hundred twenty-three thousand, three hundred eleven".