81413806247 has 4 divisors (see below), whose sum is σ = 82035285816. Its totient is φ = 80792326680.

The previous prime is 81413806237. The next prime is 81413806267. The reversal of 81413806247 is 74260831418.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74260831418 = 2 ⋅37130415709.

It is a cyclic number.

It is not a de Polignac number, because 81413806247 - 2³⁶ = 12694329511 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81413806198 and 81413806207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81413806237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 310739588 + ... + 310739849.

It is an arithmetic number, because the mean of its divisors is an integer number (20508821454).

Almost surely, 2^81413806247 is an apocalyptic number.

81413806247 is a deficient number, since it is larger than the sum of its proper divisors (621479569).

81413806247 is a wasteful number, since it uses less digits than its factorization.

81413806247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 621479568.

The product of its (nonzero) digits is 258048, while the sum is 44.

The spelling of 81413806247 in words is "eighty-one billion, four hundred thirteen million, eight hundred six thousand, two hundred forty-seven".