81245030399 has 4 divisors (see below), whose sum is σ = 87494648136. Its totient is φ = 74995412664.

The previous prime is 81245030381. The next prime is 81245030407. The reversal of 81245030399 is 99303054218.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81245030399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81245030309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3124808849 + ... + 3124808874.

It is an arithmetic number, because the mean of its divisors is an integer number (21873662034).

Almost surely, 2^81245030399 is an apocalyptic number.

81245030399 is a deficient number, since it is larger than the sum of its proper divisors (6249617737).

81245030399 is a wasteful number, since it uses less digits than its factorization.

81245030399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6249617736.

The product of its (nonzero) digits is 233280, while the sum is 44.

The spelling of 81245030399 in words is "eighty-one billion, two hundred forty-five million, thirty thousand, three hundred ninety-nine".