81336735522 has 288 divisors, whose sum is σ = 224955014400. Its totient is φ = 21694236480.

The previous prime is 81336735499. The next prime is 81336735533. The reversal of 81336735522 is 22553763318.

81336735522 is a `hidden beast` number, since 8 + 1 + 33 + 67 + 3 + 552 + 2 = 666.

It is a super-2 number, since 2×81336735522² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 73740823 + ... + 73741925.

It is an arithmetic number, because the mean of its divisors is an integer number (781093800).

Almost surely, 2^81336735522 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81336735522, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112477507200).

81336735522 is an abundant number, since it is smaller than the sum of its proper divisors (143618278878).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81336735522 is a wasteful number, since it uses less digits than its factorization.

81336735522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1219 (or 1175 counting only the distinct ones).

The product of its digits is 907200, while the sum is 45.

The spelling of 81336735522 in words is "eighty-one billion, three hundred thirty-six million, seven hundred thirty-five thousand, five hundred twenty-two".