81431542351 has 16 divisors (see below), whose sum is σ = 84826859040. Its totient is φ = 78076897920.

The previous prime is 81431542349. The next prime is 81431542363. The reversal of 81431542351 is 15324513418.

It is a cyclic number.

It is not a de Polignac number, because 81431542351 - 2¹ = 81431542349 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81431542351.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81431542321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3077560 + ... + 3103906.

It is an arithmetic number, because the mean of its divisors is an integer number (5301678690).

Almost surely, 2^81431542351 is an apocalyptic number.

81431542351 is a deficient number, since it is larger than the sum of its proper divisors (3395316689).

81431542351 is a wasteful number, since it uses less digits than its factorization.

81431542351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27114.

The product of its digits is 57600, while the sum is 37.

The spelling of 81431542351 in words is "eighty-one billion, four hundred thirty-one million, five hundred forty-two thousand, three hundred fifty-one".