81224275 has 24 divisors (see below), whose sum is σ = 110827728. Its totient is φ = 59048000.

The previous prime is 81224267. The next prime is 81224279. The reversal of 81224275 is 57242218.

It is a happy number.

It is not a de Polignac number, because 81224275 - 2³ = 81224267 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81224279) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32055 + ... + 34495.

It is an arithmetic number, because the mean of its divisors is an integer number (4617822).

Almost surely, 2^81224275 is an apocalyptic number.

81224275 is a deficient number, since it is larger than the sum of its proper divisors (29603453).

81224275 is a wasteful number, since it uses less digits than its factorization.

81224275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2484 (or 2457 counting only the distinct ones).

The product of its digits is 8960, while the sum is 31.

The square root of 81224275 is about 9012.4511094374. The cubic root of 81224275 is about 433.0738370741.

The spelling of 81224275 in words is "eighty-one million, two hundred twenty-four thousand, two hundred seventy-five".