81536630 has 32 divisors (see below), whose sum is σ = 168727104. Its totient is φ = 27789696.

The previous prime is 81536629. The next prime is 81536639. The reversal of 81536630 is 3663518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81536639) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8744 + ... + 15476.

It is an arithmetic number, because the mean of its divisors is an integer number (5272722).

Almost surely, 2^81536630 is an apocalyptic number.

81536630 is an abundant number, since it is smaller than the sum of its proper divisors (87190474).

81536630 is a wasteful number, since it uses less digits than its factorization.

81536630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6920.

The product of its (nonzero) digits is 12960, while the sum is 32.

The square root of 81536630 is about 9029.7635627961. The cubic root of 81536630 is about 433.6282679870.

The spelling of 81536630 in words is "eighty-one million, five hundred thirty-six thousand, six hundred thirty".