81224405 has 16 divisors (see below), whose sum is σ = 99047424. Its totient is φ = 63936000.

The previous prime is 81224387. The next prime is 81224417. The reversal of 81224405 is 50442218.

It is a happy number.

It is not a de Polignac number, because 81224405 - 2¹² = 81220309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107780 + ... + 108530.

It is an arithmetic number, because the mean of its divisors is an integer number (6190464).

Almost surely, 2^81224405 is an apocalyptic number.

It is an amenable number.

81224405 is a deficient number, since it is larger than the sum of its proper divisors (17823019).

81224405 is a wasteful number, since it uses less digits than its factorization.

81224405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1076.

The product of its (nonzero) digits is 2560, while the sum is 26.

The square root of 81224405 is about 9012.4583216789. The cubic root of 81224405 is about 433.0740681198.

The spelling of 81224405 in words is "eighty-one million, two hundred twenty-four thousand, four hundred five".