81447252 has 24 divisors (see below), whose sum is σ = 190191456. Its totient is φ = 27127968.

The previous prime is 81447251. The next prime is 81447263. The reversal of 81447252 is 25274418.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81447251) 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 7 ways as a sum of consecutive naturals, for example, 25023 + ... + 28089.

It is an arithmetic number, because the mean of its divisors is an integer number (7924644).

Almost surely, 2^81447252 is an apocalyptic number.

It is an amenable number.

81447252 is an abundant number, since it is smaller than the sum of its proper divisors (108744204).

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

81447252 is a wasteful number, since it uses less digits than its factorization.

81447252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5287 (or 5285 counting only the distinct ones).

The product of its digits is 17920, while the sum is 33.

The square root of 81447252 is about 9024.8131282592. The cubic root of 81447252 is about 433.4697666389.

The spelling of 81447252 in words is "eighty-one million, four hundred forty-seven thousand, two hundred fifty-two".