81204823 has 8 divisors (see below), whose sum is σ = 92994048. Its totient is φ = 69462744.

The previous prime is 81204821. The next prime is 81204857. The reversal of 81204823 is 32840218.

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

It is a cyclic number.

It is not a de Polignac number, because 81204823 - 2¹ = 81204821 is a prime.

It is a super-2 number, since 2×81204823² = 13188446556922658, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81204791 and 81204800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81204821) 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, 8011 + ... + 15052.

It is an arithmetic number, because the mean of its divisors is an integer number (11624256).

Almost surely, 2^81204823 is an apocalyptic number.

81204823 is a deficient number, since it is larger than the sum of its proper divisors (11789225).

81204823 is a wasteful number, since it uses less digits than its factorization.

81204823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23573.

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 81204823 is about 9011.3718711415. The cubic root of 81204823 is about 433.0392627433.

The spelling of 81204823 in words is "eighty-one million, two hundred four thousand, eight hundred twenty-three".