81535556 has 12 divisors (see below), whose sum is σ = 142795968. Its totient is φ = 40736712.

The previous prime is 81535469. The next prime is 81535577. The reversal of 81535556 is 65553518.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1256 + ... + 12831.

It is an arithmetic number, because the mean of its divisors is an integer number (11899664).

Almost surely, 2^81535556 is an apocalyptic number.

It is an amenable number.

81535556 is a deficient number, since it is larger than the sum of its proper divisors (61260412).

81535556 is a wasteful number, since it uses less digits than its factorization.

81535556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15538 (or 15536 counting only the distinct ones).

The product of its digits is 90000, while the sum is 38.

The square root of 81535556 is about 9029.7040926046. The cubic root of 81535556 is about 433.6263640624.

The spelling of 81535556 in words is "eighty-one million, five hundred thirty-five thousand, five hundred fifty-six".