81227380 has 24 divisors (see below), whose sum is σ = 183699432. Its totient is φ = 29991552.

The previous prime is 81227371. The next prime is 81227381. The reversal of 81227380 is 8372218.

It can be written as a sum of positive squares in 4 ways, for example, as 11236 + 81216144 = 106^2 + 9012^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81227381) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155947 + ... + 156466.

It is an arithmetic number, because the mean of its divisors is an integer number (7654143).

Almost surely, 2^81227380 is an apocalyptic number.

It is an amenable number.

81227380 is an abundant number, since it is smaller than the sum of its proper divisors (102472052).

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

81227380 is a wasteful number, since it uses less digits than its factorization.

81227380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312435 (or 312433 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 81227380 is about 9012.6233694746. The cubic root of 81227380 is about 433.0793554454.

Adding to 81227380 its reverse (8372218), we get a palindrome (89599598).

The spelling of 81227380 in words is "eighty-one million, two hundred twenty-seven thousand, three hundred eighty".