81536223 has 16 divisors (see below), whose sum is σ = 109947776. Its totient is φ = 53745120.

The previous prime is 81536183. The next prime is 81536269. The reversal of 81536223 is 32263518.

It is not a de Polignac number, because 81536223 - 2⁸ = 81535967 is a prime.

It is a super-2 number, since 2×81536223² = 13296311322211458, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81536423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 155640 + ... + 156162.

It is an arithmetic number, because the mean of its divisors is an integer number (6871736).

Almost surely, 2^81536223 is an apocalyptic number.

81536223 is a deficient number, since it is larger than the sum of its proper divisors (28411553).

81536223 is a wasteful number, since it uses less digits than its factorization.

81536223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1014.

The product of its digits is 8640, while the sum is 30.

The square root of 81536223 is about 9029.7410261867. The cubic root of 81536223 is about 433.6275464831.

The spelling of 81536223 in words is "eighty-one million, five hundred thirty-six thousand, two hundred twenty-three".