81393624390 has 64 divisors (see below), whose sum is σ = 210562027200. Its totient is φ = 20017181184.

The previous prime is 81393624383. The next prime is 81393624479. The reversal of 81393624390 is 9342639318.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 338416 + ... + 526604.

It is an arithmetic number, because the mean of its divisors is an integer number (3290031675).

Almost surely, 2^81393624390 is an apocalyptic number.

81393624390 is an abundant number, since it is smaller than the sum of its proper divisors (129168402810).

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

81393624390 is a wasteful number, since it uses less digits than its factorization.

81393624390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189321.

The product of its (nonzero) digits is 839808, while the sum is 48.

The spelling of 81393624390 in words is "eighty-one billion, three hundred ninety-three million, six hundred twenty-four thousand, three hundred ninety".