81543268407 has 4 divisors (see below), whose sum is σ = 108724357880. Its totient is φ = 54362178936.

The previous prime is 81543268381. The next prime is 81543268421. The reversal of 81543268407 is 70486234518.

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

It is not a de Polignac number, because 81543268407 - 2⁶ = 81543268343 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 (81543268427) 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, 13590544732 + ... + 13590544737.

It is an arithmetic number, because the mean of its divisors is an integer number (27181089470).

Almost surely, 2^81543268407 is an apocalyptic number.

81543268407 is a deficient number, since it is larger than the sum of its proper divisors (27181089473).

81543268407 is a wasteful number, since it uses less digits than its factorization.

81543268407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27181089472.

The product of its (nonzero) digits is 1290240, while the sum is 48.

The spelling of 81543268407 in words is "eighty-one billion, five hundred forty-three million, two hundred sixty-eight thousand, four hundred seven".