81854201529 has 12 divisors (see below), whose sum is σ = 121429356516. Its totient is φ = 53094616992.

The previous prime is 81854201519. The next prime is 81854201531. The reversal of 81854201529 is 92510245818.

81854201529 is a `hidden beast` number, since 8 + 1 + 85 + 42 + 0 + 1 + 529 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 64047967929 + 17806233600 = 253077^2 + 133440^2 .

It is not a de Polignac number, because 81854201529 - 2⁵ = 81854201497 is a prime.

It is a super-2 number, since 2×81854201529² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81854201509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 122903874 + ... + 122904539.

It is an arithmetic number, because the mean of its divisors is an integer number (10119113043).

Almost surely, 2^81854201529 is an apocalyptic number.

It is an amenable number.

81854201529 is a deficient number, since it is larger than the sum of its proper divisors (39575154987).

81854201529 is a wasteful number, since it uses less digits than its factorization.

81854201529 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245808456 (or 245808453 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 45.

The spelling of 81854201529 in words is "eighty-one billion, eight hundred fifty-four million, two hundred one thousand, five hundred twenty-nine".