81072636 has 12 divisors (see below), whose sum is σ = 189169512. Its totient is φ = 27024208.

The previous prime is 81072617. The next prime is 81072647. The reversal of 81072636 is 63627018.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 81072597 and 81072606.

It is a congruent number.

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, 3378015 + ... + 3378038.

It is an arithmetic number, because the mean of its divisors is an integer number (15764126).

Almost surely, 2^81072636 is an apocalyptic number.

It is an amenable number.

81072636 is an abundant number, since it is smaller than the sum of its proper divisors (108096876).

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

81072636 is a wasteful number, since it uses less digits than its factorization.

81072636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6756060 (or 6756058 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 33.

The square root of 81072636 is about 9004.0344290768. The cubic root of 81072636 is about 432.8041648471.

The spelling of 81072636 in words is "eighty-one million, seventy-two thousand, six hundred thirty-six".