81963090 has 80 divisors (see below), whose sum is σ = 240451200. Its totient is φ = 19867680.

The previous prime is 81963071. The next prime is 81963097. The reversal of 81963090 is 9036918.

81963090 is a `hidden beast` number, since 8 + 19 + 630 + 9 + 0 = 666.

It is not an unprimeable number, because it can be changed into a prime (81963097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4311 + ... + 13509.

It is an arithmetic number, because the mean of its divisors is an integer number (3005640).

Almost surely, 2^81963090 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81963090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120225600).

81963090 is an abundant number, since it is smaller than the sum of its proper divisors (158488110).

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

81963090 is a wasteful number, since it uses less digits than its factorization.

81963090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9229 (or 9220 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 81963090 is about 9053.3468949334. The cubic root of 81963090 is about 434.3829539113.

The spelling of 81963090 in words is "eighty-one million, nine hundred sixty-three thousand, ninety".