81436224 has 28 divisors (see below), whose sum is σ = 215467184. Its totient is φ = 27145344.

The previous prime is 81436211. The next prime is 81436237. The reversal of 81436224 is 42263418.

It is an interprime number because it is at equal distance from previous prime (81436211) and next prime (81436237).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 81436191 and 81436200.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 211882 + ... + 212265.

Almost surely, 2^81436224 is an apocalyptic number.

It is an amenable number.

81436224 is an abundant number, since it is smaller than the sum of its proper divisors (134030960).

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

81436224 is a wasteful number, since it uses less digits than its factorization.

81436224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424162 (or 424152 counting only the distinct ones).

The product of its digits is 9216, while the sum is 30.

The square root of 81436224 is about 9024.2021253959. The cubic root of 81436224 is about 433.4502017458.

The spelling of 81436224 in words is "eighty-one million, four hundred thirty-six thousand, two hundred twenty-four".