81264222 has 80 divisors (see below), whose sum is σ = 200515392. Its totient is φ = 24442560.

The previous prime is 81264217. The next prime is 81264223. The reversal of 81264222 is 22246218.

It is a happy number.

81264222 is a `hidden beast` number, since 8 + 12 + 642 + 2 + 2 = 666.

It is a super-4 number, since 4×81264222⁴ (a number of 33 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81264223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 98572 + ... + 99392.

Almost surely, 2^81264222 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81264222, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100257696).

81264222 is an abundant number, since it is smaller than the sum of its proper divisors (119251170).

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

81264222 is a wasteful number, since it uses less digits than its factorization.

81264222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 895 (or 886 counting only the distinct ones).

The product of its digits is 3072, while the sum is 27.

The square root of 81264222 is about 9014.6670487600. The cubic root of 81264222 is about 433.1448222783.

The spelling of 81264222 in words is "eighty-one million, two hundred sixty-four thousand, two hundred twenty-two".