81420950992 has 40 divisors (see below), whose sum is σ = 158901704640. Its totient is φ = 40414828800.

The previous prime is 81420950983. The next prime is 81420950999. The reversal of 81420950992 is 29905902418.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81420950999) 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, 1697613 + ... + 1744915.

It is an arithmetic number, because the mean of its divisors is an integer number (3972542616).

Almost surely, 2^81420950992 is an apocalyptic number.

It is an amenable number.

81420950992 is a deficient number, since it is larger than the sum of its proper divisors (77480753648).

81420950992 is a wasteful number, since it uses less digits than its factorization.

81420950992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48091 (or 48085 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 49.

The spelling of 81420950992 in words is "eighty-one billion, four hundred twenty million, nine hundred fifty thousand, nine hundred ninety-two".