81006630 has 32 divisors (see below), whose sum is σ = 195174144. Its totient is φ = 21517536.

The previous prime is 81006619. The next prime is 81006637. The reversal of 81006630 is 3660018.

It is a self number, because there is not a number n which added to its sum of digits gives 81006630.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81006637) 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, 2757 + ... + 13023.

It is an arithmetic number, because the mean of its divisors is an integer number (6099192).

Almost surely, 2^81006630 is an apocalyptic number.

81006630 is an abundant number, since it is smaller than the sum of its proper divisors (114167514).

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

81006630 is a wasteful number, since it uses less digits than its factorization.

81006630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10540.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 81006630 is about 9000.3683257965. The cubic root of 81006630 is about 432.6866758500.

Adding to 81006630 its reverse (3660018), we get a palindrome (84666648).

The spelling of 81006630 in words is "eighty-one million, six thousand, six hundred thirty".