81530635 has 4 divisors (see below), whose sum is σ = 97836768. Its totient is φ = 65224504.

The previous prime is 81530633. The next prime is 81530639. The reversal of 81530635 is 53603518.

81530635 = T₇₃₇₁ + T₇₃₇₂ + T₇₃₇₃.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81530635 - 2¹ = 81530633 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81530597 and 81530606.

It is not an unprimeable number, because it can be changed into a prime (81530633) by changing a digit.

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, 8153059 + ... + 8153068.

It is an arithmetic number, because the mean of its divisors is an integer number (24459192).

Almost surely, 2^81530635 is an apocalyptic number.

81530635 is the 7373-rd centered triangular number.

81530635 is a deficient number, since it is larger than the sum of its proper divisors (16306133).

81530635 is a wasteful number, since it uses less digits than its factorization.

81530635 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16306132.

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 81530635 is about 9029.4315989435. The cubic root of 81530635 is about 433.6176401863.

The spelling of 81530635 in words is "eighty-one million, five hundred thirty thousand, six hundred thirty-five".