81384624 has 30 divisors (see below), whose sum is σ = 227764316. Its totient is φ = 27128160.

The previous prime is 81384623. The next prime is 81384629. The reversal of 81384624 is 42648318.

It is a Harshad number since it is a multiple of its sum of digits (36).

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

It is not an unprimeable number, because it can be changed into a prime (81384623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 282442 + ... + 282729.

Almost surely, 2^81384624 is an apocalyptic number.

It is an amenable number.

81384624 is an abundant number, since it is smaller than the sum of its proper divisors (146379692).

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

81384624 is a wasteful number, since it uses less digits than its factorization.

81384624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 565185 (or 565176 counting only the distinct ones).

The product of its digits is 36864, while the sum is 36.

The square root of 81384624 is about 9021.3426938566. The cubic root of 81384624 is about 433.3586341572.

The spelling of 81384624 in words is "eighty-one million, three hundred eighty-four thousand, six hundred twenty-four".