81992139430 has 16 divisors (see below), whose sum is σ = 147589113600. Its totient is φ = 32796130752.

The previous prime is 81992139409. The next prime is 81992139469. The reversal of 81992139430 is 3493129918.

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 7 ways as a sum of consecutive naturals, for example, 821371 + ... + 915769.

It is an arithmetic number, because the mean of its divisors is an integer number (9224319600).

Almost surely, 2^81992139430 is an apocalyptic number.

81992139430 is a deficient number, since it is larger than the sum of its proper divisors (65596974170).

81992139430 is a wasteful number, since it uses less digits than its factorization.

81992139430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181263.

The product of its (nonzero) digits is 419904, while the sum is 49.

The spelling of 81992139430 in words is "eighty-one billion, nine hundred ninety-two million, one hundred thirty-nine thousand, four hundred thirty".