81999828355752 has 48 divisors (see below), whose sum is σ = 222297856921140. Its totient is φ = 27306816000768.

The previous prime is 81999828355747. The next prime is 81999828355759. The reversal of 81999828355752 is 25755382899918.

81999828355752 is a `hidden beast` number, since 8 + 1 + 9 + 9 + 9 + 8 + 2 + 8 + 3 + 557 + 52 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 61859892391236 + 20139935964516 = 7865106^2 + 4487754^2 .

It is not an unprimeable number, because it can be changed into a prime (81999828355759) 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, 551177563 + ... + 551326314.

Almost surely, 2^{81999828355752} is an apocalyptic number.

It is an amenable number.

81999828355752 is an abundant number, since it is smaller than the sum of its proper divisors (140298028565388).

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

81999828355752 is a wasteful number, since it uses less digits than its factorization.

81999828355752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1102504922 (or 1102504915 counting only the distinct ones).

The product of its digits is 3919104000, while the sum is 81.

The spelling of 81999828355752 in words is "eighty-one trillion, nine hundred ninety-nine billion, eight hundred twenty-eight million, three hundred fifty-five thousand, seven hundred fifty-two".