81200051285 has 16 divisors (see below), whose sum is σ = 103313822976. Its totient is φ = 61054718208.

The previous prime is 81200051269. The next prime is 81200051311. The reversal of 81200051285 is 58215000218.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81200051285 - 2⁴ = 81200051269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 595217 + ... + 718806.

It is an arithmetic number, because the mean of its divisors is an integer number (6457113936).

Almost surely, 2^81200051285 is an apocalyptic number.

81200051285 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

81200051285 is a deficient number, since it is larger than the sum of its proper divisors (22113771691).

81200051285 is a wasteful number, since it uses less digits than its factorization.

81200051285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1314772.

The product of its (nonzero) digits is 6400, while the sum is 32.

The spelling of 81200051285 in words is "eighty-one billion, two hundred million, fifty-one thousand, two hundred eighty-five".