81030536 has 8 divisors (see below), whose sum is σ = 151932270. Its totient is φ = 40515264.

The previous prime is 81030503. The next prime is 81030557. The reversal of 81030536 is 63503018.

It can be written as a sum of positive squares in only one way, i.e., 68989636 + 12040900 = 8306^2 + 3470^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5064401 + ... + 5064416.

Almost surely, 2^81030536 is an apocalyptic number.

It is an amenable number.

81030536 is a deficient number, since it is larger than the sum of its proper divisors (70901734).

81030536 is a wasteful number, since it uses less digits than its factorization.

81030536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10128823 (or 10128819 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 81030536 is about 9001.6962845899. The cubic root of 81030536 is about 432.7292352895.

The spelling of 81030536 in words is "eighty-one million, thirty thousand, five hundred thirty-six".