81220484 has 12 divisors (see below), whose sum is σ = 143078208. Its totient is φ = 40341000.

The previous prime is 81220471. The next prime is 81220487. The reversal of 81220484 is 48402218.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (81220487) 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 3 ways as a sum of consecutive naturals, for example, 66632 + ... + 67839.

It is an arithmetic number, because the mean of its divisors is an integer number (11923184).

Almost surely, 2^81220484 is an apocalyptic number.

It is an amenable number.

81220484 is a deficient number, since it is larger than the sum of its proper divisors (61857724).

81220484 is a wasteful number, since it uses less digits than its factorization.

81220484 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134626 (or 134624 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 29.

The square root of 81220484 is about 9012.2407868410. The cubic root of 81220484 is about 433.0670993164.

The spelling of 81220484 in words is "eighty-one million, two hundred twenty thousand, four hundred eighty-four".