81215850299 has 2 divisors, whose sum is σ = 81215850300. Its totient is φ = 81215850298.

The previous prime is 81215850281. The next prime is 81215850301. The reversal of 81215850299 is 99205851218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81215850299 - 2¹⁶ = 81215784763 is a prime.

Together with 81215850301, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81215820299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40607925149 + 40607925150.

It is an arithmetic number, because the mean of its divisors is an integer number (40607925150).

Almost surely, 2^81215850299 is an apocalyptic number.

81215850299 is a deficient number, since it is larger than the sum of its proper divisors (1).

81215850299 is an equidigital number, since it uses as much as digits as its factorization.

81215850299 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 518400, while the sum is 50.

The spelling of 81215850299 in words is "eighty-one billion, two hundred fifteen million, eight hundred fifty thousand, two hundred ninety-nine".