81224430 has 64 divisors (see below), whose sum is σ = 234524160. Its totient is φ = 17587584.

The previous prime is 81224417. The next prime is 81224441. The reversal of 81224430 is 3442218.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81224430.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6189 + ... + 14168.

It is an arithmetic number, because the mean of its divisors is an integer number (3664440).

Almost surely, 2^81224430 is an apocalyptic number.

81224430 is an abundant number, since it is smaller than the sum of its proper divisors (153299730).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81224430 is a wasteful number, since it uses less digits than its factorization.

81224430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20393.

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 81224430 is about 9012.4597086478. The cubic root of 81224430 is about 433.0741125517.

Adding to 81224430 its reverse (3442218), we get a palindrome (84666648).

The spelling of 81224430 in words is "eighty-one million, two hundred twenty-four thousand, four hundred thirty".