81302223 has 4 divisors (see below), whose sum is σ = 108402968. Its totient is φ = 54201480.

The previous prime is 81302219. The next prime is 81302227. The reversal of 81302223 is 32220318.

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 (81302219) and next prime (81302227).

It is not a de Polignac number, because 81302223 - 2² = 81302219 is a prime.

It is a super-2 number, since 2×81302223² = 13220102929483458, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81302223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81302227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13550368 + ... + 13550373.

It is an arithmetic number, because the mean of its divisors is an integer number (27100742).

Almost surely, 2^81302223 is an apocalyptic number.

81302223 is a deficient number, since it is larger than the sum of its proper divisors (27100745).

81302223 is a wasteful number, since it uses less digits than its factorization.

81302223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27100744.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 81302223 is about 9016.7745341669. The cubic root of 81302223 is about 433.2123278831.

The spelling of 81302223 in words is "eighty-one million, three hundred two thousand, two hundred twenty-three".