81935055049 has 3 divisors (see below), whose sum is σ = 81935341293. Its totient is φ = 81934768806.

The previous prime is 81935055047. The next prime is 81935055053. The reversal of 81935055049 is 94055053918.

The square root of 81935055049 is 286243.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 81935055049 - 2¹ = 81935055047 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81935054993 and 81935055011.

It is not an unprimeable number, because it can be changed into a prime (81935055043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 143122 + ... + 429364.

It is an arithmetic number, because the mean of its divisors is an integer number (27311780431).

Almost surely, 2^81935055049 is an apocalyptic number.

81935055049 is the 286243-rd square number.

81935055049 is the 143122-nd centered octagonal number.

It is an amenable number.

81935055049 is a deficient number, since it is larger than the sum of its proper divisors (286244).

81935055049 is an frugal number, since it uses more digits than its factorization.

81935055049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 572486 (or 286243 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 49.

Multiplying 81935055049 by its sum of digits (49), we get a square (4014817697401 = 2003701²).

The spelling of 81935055049 in words is "eighty-one billion, nine hundred thirty-five million, fifty-five thousand, forty-nine".