81067522819 has 4 divisors (see below), whose sum is σ = 81135024040. Its totient is φ = 81000021600.

The previous prime is 81067522801. The next prime is 81067522897. The reversal of 81067522819 is 91822576018.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81067522819 - 2⁹ = 81067522307 is a prime.

It is a super-4 number, since 4×81067522819⁴ (a number of 45 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81067522619) 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, 33748809 + ... + 33751210.

It is an arithmetic number, because the mean of its divisors is an integer number (20283756010).

Almost surely, 2^81067522819 is an apocalyptic number.

81067522819 is a deficient number, since it is larger than the sum of its proper divisors (67501221).

81067522819 is a wasteful number, since it uses less digits than its factorization.

81067522819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67501220.

The product of its (nonzero) digits is 483840, while the sum is 49.

The spelling of 81067522819 in words is "eighty-one billion, sixty-seven million, five hundred twenty-two thousand, eight hundred nineteen".