81867202559 has 4 divisors (see below), whose sum is σ = 82046343504. Its totient is φ = 81688061616.

The previous prime is 81867202523. The next prime is 81867202597. The reversal of 81867202559 is 95520276818.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 95520276818 = 2 ⋅47760138409.

It is a cyclic number.

It is not a de Polignac number, because 81867202559 - 2⁸ = 81867202303 is a prime.

It is a super-2 number, since 2×81867202559² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81867202559.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81867208559) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 89569787 + ... + 89570700.

It is an arithmetic number, because the mean of its divisors is an integer number (20511585876).

Almost surely, 2^81867202559 is an apocalyptic number.

81867202559 is a deficient number, since it is larger than the sum of its proper divisors (179140945).

81867202559 is a wasteful number, since it uses less digits than its factorization.

81867202559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179140944.

The product of its (nonzero) digits is 2419200, while the sum is 53.

The spelling of 81867202559 in words is "eighty-one billion, eight hundred sixty-seven million, two hundred two thousand, five hundred fifty-nine".