81651123284 has 48 divisors (see below), whose sum is σ = 152417538000. Its totient is φ = 38139273216.

The previous prime is 81651123283. The next prime is 81651123289. The reversal of 81651123284 is 48232115618.

It can be written as a sum of positive squares in 8 ways, for example, as 12181978384 + 69469144900 = 110372^2 + 263570^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81651123283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27648752 + ... + 27651704.

It is an arithmetic number, because the mean of its divisors is an integer number (3175365375).

Almost surely, 2^81651123284 is an apocalyptic number.

It is an amenable number.

81651123284 is a deficient number, since it is larger than the sum of its proper divisors (70766414716).

81651123284 is a wasteful number, since it uses less digits than its factorization.

81651123284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5852 (or 5850 counting only the distinct ones).

The product of its digits is 92160, while the sum is 41.

The spelling of 81651123284 in words is "eighty-one billion, six hundred fifty-one million, one hundred twenty-three thousand, two hundred eighty-four".