81455536 has 30 divisors (see below), whose sum is σ = 159960620. Its totient is φ = 40182624.

The previous prime is 81455533. The next prime is 81455567. The reversal of 81455536 is 63555418.

It is a junction number, because it is equal to n+sod(n) for n = 81455495 and 81455504.

It is not an unprimeable number, because it can be changed into a prime (81455533) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 109855 + ... + 110593.

Almost surely, 2^81455536 is an apocalyptic number.

It is an amenable number.

81455536 is a deficient number, since it is larger than the sum of its proper divisors (78505084).

81455536 is an equidigital number, since it uses as much as digits as its factorization.

81455536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 913 (or 824 counting only the distinct ones).

The product of its digits is 72000, while the sum is 37.

The square root of 81455536 is about 9025.2720734613. The cubic root of 81455536 is about 433.4844622107.

The spelling of 81455536 in words is "eighty-one million, four hundred fifty-five thousand, five hundred thirty-six".