81251351543 has 16 divisors (see below), whose sum is σ = 82733654016. Its totient is φ = 79779110880.

The previous prime is 81251351507. The next prime is 81251351563. The reversal of 81251351543 is 34515315218.

It is a cyclic number.

It is not a de Polignac number, because 81251351543 - 2²⁰ = 81250302967 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81251351497 and 81251351506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81251351563) 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, 22486805 + ... + 22490417.

It is an arithmetic number, because the mean of its divisors is an integer number (5170853376).

Almost surely, 2^81251351543 is an apocalyptic number.

81251351543 is a deficient number, since it is larger than the sum of its proper divisors (1482302473).

81251351543 is a wasteful number, since it uses less digits than its factorization.

81251351543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4894.

The product of its digits is 72000, while the sum is 38.

The spelling of 81251351543 in words is "eighty-one billion, two hundred fifty-one million, three hundred fifty-one thousand, five hundred forty-three".