81443861878219 has 8 divisors (see below), whose sum is σ = 81450224032320. Its totient is φ = 81437500025856.

The previous prime is 81443861878201. The next prime is 81443861878277. The reversal of 81443861878219 is 91287816834418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81443861878219 is a prime.

It is a super-2 number, since 2×81443861878219² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81443861878279) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 899558877 + ... + 899649409.

It is an arithmetic number, because the mean of its divisors is an integer number (10181278004040).

Almost surely, 2^{81443861878219} is an apocalyptic number.

81443861878219 is a deficient number, since it is larger than the sum of its proper divisors (6362154101).

81443861878219 is a wasteful number, since it uses less digits than its factorization.

81443861878219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150869.

The product of its digits is 148635648, while the sum is 70.

The spelling of 81443861878219 in words is "eighty-one trillion, four hundred forty-three billion, eight hundred sixty-one million, eight hundred seventy-eight thousand, two hundred nineteen".