81048523549 has 12 divisors (see below), whose sum is σ = 94296455004. Its totient is φ = 69458727744.

The previous prime is 81048523547. The next prime is 81048523561. The reversal of 81048523549 is 94532584018.

It can be written as a sum of positive squares in 2 ways, for example, as 59593597924 + 21454925625 = 244118^2 + 146475^2 .

It is not a de Polignac number, because 81048523549 - 2¹ = 81048523547 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81048523547) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 171607 + ... + 437659.

It is an arithmetic number, because the mean of its divisors is an integer number (7858037917).

Almost surely, 2^81048523549 is an apocalyptic number.

It is an amenable number.

81048523549 is a deficient number, since it is larger than the sum of its proper divisors (13247931455).

81048523549 is a wasteful number, since it uses less digits than its factorization.

81048523549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272284 (or 272277 counting only the distinct ones).

The product of its (nonzero) digits is 1382400, while the sum is 49.

The spelling of 81048523549 in words is "eighty-one billion, forty-eight million, five hundred twenty-three thousand, five hundred forty-nine".