81227642252 has 6 divisors (see below), whose sum is σ = 142148373948. Its totient is φ = 40613821124.

The previous prime is 81227642233. The next prime is 81227642257. The reversal of 81227642252 is 25224672218.

It is not an unprimeable number, because it can be changed into a prime (81227642257) 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 as a sum of consecutive naturals, namely, 10153455278 + ... + 10153455285.

It is an arithmetic number, because the mean of its divisors is an integer number (23691395658).

Almost surely, 2^81227642252 is an apocalyptic number.

It is an amenable number.

81227642252 is a deficient number, since it is larger than the sum of its proper divisors (60920731696).

81227642252 is a wasteful number, since it uses less digits than its factorization.

81227642252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20306910567 (or 20306910565 counting only the distinct ones).

The product of its digits is 215040, while the sum is 41.

The spelling of 81227642252 in words is "eighty-one billion, two hundred twenty-seven million, six hundred forty-two thousand, two hundred fifty-two".