81222800 has 30 divisors (see below), whose sum is σ = 195138738. Its totient is φ = 32488960.

The previous prime is 81222797. The next prime is 81222803. The reversal of 81222800 is 822218.

It is an interprime number because it is at equal distance from previous prime (81222797) and next prime (81222803).

It can be written as a sum of positive squares in 3 ways, for example, as 1227664 + 79995136 = 1108^2 + 8944^2 .

It is not an unprimeable number, because it can be changed into a prime (81222803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 101129 + ... + 101928.

Almost surely, 2^81222800 is an apocalyptic number.

81222800 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81222800 is an abundant number, since it is smaller than the sum of its proper divisors (113915938).

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

81222800 is a wasteful number, since it uses less digits than its factorization.

81222800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203075 (or 203064 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 23.

The square root of 81222800 is about 9012.3692778314. The cubic root of 81222800 is about 433.0712155763.

The spelling of 81222800 in words is "eighty-one million, two hundred twenty-two thousand, eight hundred".