81244780 has 24 divisors (see below), whose sum is σ = 174777120. Its totient is φ = 31704960.

The previous prime is 81244777. The next prime is 81244781. The reversal of 81244780 is 8744218.

It is not an unprimeable number, because it can be changed into a prime (81244781) 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, 48720 + ... + 50359.

It is an arithmetic number, because the mean of its divisors is an integer number (7282380).

Almost surely, 2^81244780 is an apocalyptic number.

It is an amenable number.

81244780 is an abundant number, since it is smaller than the sum of its proper divisors (93532340).

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

81244780 is a wasteful number, since it uses less digits than its factorization.

81244780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99129 (or 99127 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 34.

The square root of 81244780 is about 9013.5886305067. The cubic root of 81244780 is about 433.1102770500.

Adding to 81244780 its reverse (8744218), we get a palindrome (89988998).

The spelling of 81244780 in words is "eighty-one million, two hundred forty-four thousand, seven hundred eighty".