81651519547 has 16 divisors (see below), whose sum is σ = 88786833408. Its totient is φ = 74639416320.

The previous prime is 81651519533. The next prime is 81651519559. The reversal of 81651519547 is 74591515618.

It is a cyclic number.

It is not a de Polignac number, because 81651519547 - 2¹¹ = 81651517499 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81651519494 and 81651519503.

It is not an unprimeable number, because it can be changed into a prime (81651510547) 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 15 ways as a sum of consecutive naturals, for example, 1729222 + ... + 1775812.

It is an arithmetic number, because the mean of its divisors is an integer number (5549177088).

Almost surely, 2^81651519547 is an apocalyptic number.

81651519547 is a deficient number, since it is larger than the sum of its proper divisors (7135313861).

81651519547 is a wasteful number, since it uses less digits than its factorization.

81651519547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47910.

The product of its digits is 1512000, while the sum is 52.

The spelling of 81651519547 in words is "eighty-one billion, six hundred fifty-one million, five hundred nineteen thousand, five hundred forty-seven".