81226656 has 144 divisors (see below), whose sum is σ = 270414144. Its totient is φ = 22643712.

The previous prime is 81226637. The next prime is 81226667. The reversal of 81226656 is 65662218.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 81226656.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 86220 + ... + 87156.

It is an arithmetic number, because the mean of its divisors is an integer number (1877876).

Almost surely, 2^81226656 is an apocalyptic number.

81226656 is a gapful number since it is divisible by the number (86) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81226656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135207072).

81226656 is an abundant number, since it is smaller than the sum of its proper divisors (189187488).

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

81226656 is a wasteful number, since it uses less digits than its factorization.

81226656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1003 (or 992 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 81226656 is about 9012.5832034994. The cubic root of 81226656 is about 433.0780687267.

The spelling of 81226656 in words is "eighty-one million, two hundred twenty-six thousand, six hundred fifty-six".