81217122252 has 24 divisors (see below), whose sum is σ = 216578992896. Its totient is φ = 23204892048.

The previous prime is 81217122251. The next prime is 81217122257. The reversal of 81217122252 is 25222171218.

It is not an unprimeable number, because it can be changed into a prime (81217122251) 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, 483435168 + ... + 483435335.

It is an arithmetic number, because the mean of its divisors is an integer number (9024124704).

Almost surely, 2^81217122252 is an apocalyptic number.

It is an amenable number.

81217122252 is an abundant number, since it is smaller than the sum of its proper divisors (135361870644).

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

81217122252 is a wasteful number, since it uses less digits than its factorization.

81217122252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 966870517 (or 966870515 counting only the distinct ones).

The product of its digits is 8960, while the sum is 33.

The spelling of 81217122252 in words is "eighty-one billion, two hundred seventeen million, one hundred twenty-two thousand, two hundred fifty-two".