81550536 has 16 divisors (see below), whose sum is σ = 203876400. Its totient is φ = 27183504.

The previous prime is 81550507. The next prime is 81550543. The reversal of 81550536 is 63505518.

It is a junction number, because it is equal to n+sod(n) for n = 81550497 and 81550506.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1698946 + ... + 1698993.

It is an arithmetic number, because the mean of its divisors is an integer number (12742275).

Almost surely, 2^81550536 is an apocalyptic number.

It is an amenable number.

81550536 is an abundant number, since it is smaller than the sum of its proper divisors (122325864).

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

81550536 is a wasteful number, since it uses less digits than its factorization.

81550536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3397948 (or 3397944 counting only the distinct ones).

The product of its (nonzero) digits is 18000, while the sum is 33.

The square root of 81550536 is about 9030.5335390552. The cubic root of 81550536 is about 433.6529182247.

The spelling of 81550536 in words is "eighty-one million, five hundred fifty thousand, five hundred thirty-six".