81239343427 has 8 divisors (see below), whose sum is σ = 88720147440. Its totient is φ = 73774440960.

The previous prime is 81239343403. The next prime is 81239343439. The reversal of 81239343427 is 72434393218.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-81239343427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81239383427) 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, 3964698 + ... + 3985135.

It is an arithmetic number, because the mean of its divisors is an integer number (11090018430).

Almost surely, 2^81239343427 is an apocalyptic number.

81239343427 is a deficient number, since it is larger than the sum of its proper divisors (7480804013).

81239343427 is a wasteful number, since it uses less digits than its factorization.

81239343427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7950773.

The product of its digits is 870912, while the sum is 46.

The spelling of 81239343427 in words is "eighty-one billion, two hundred thirty-nine million, three hundred forty-three thousand, four hundred twenty-seven".