81224637 has 8 divisors (see below), whose sum is σ = 116630304. Its totient is φ = 49984368.

The previous prime is 81224617. The next prime is 81224641. The reversal of 81224637 is 73642218.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81224637 - 2¹² = 81220541 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81224598 and 81224607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81224617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1041303 + ... + 1041380.

It is an arithmetic number, because the mean of its divisors is an integer number (14578788).

Almost surely, 2^81224637 is an apocalyptic number.

It is an amenable number.

81224637 is a deficient number, since it is larger than the sum of its proper divisors (35405667).

81224637 is a wasteful number, since it uses less digits than its factorization.

81224637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2082699.

The product of its digits is 16128, while the sum is 33.

The square root of 81224637 is about 9012.4711927418. The cubic root of 81224637 is about 433.0744804470.

The spelling of 81224637 in words is "eighty-one million, two hundred twenty-four thousand, six hundred thirty-seven".