81204480 has 432 divisors, whose sum is σ = 344373120. Its totient is φ = 17252352.

The previous prime is 81204463. The next prime is 81204491. The reversal of 81204480 is 8440218.

81204480 = T₂₆₇ + T₂₆₈ + ... + T₇₉₆.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1532134 + ... + 1532186.

It is an arithmetic number, because the mean of its divisors is an integer number (797160).

Almost surely, 2^81204480 is an apocalyptic number.

81204480 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81204480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (172186560).

81204480 is an abundant number, since it is smaller than the sum of its proper divisors (263168640).

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

81204480 is a wasteful number, since it uses less digits than its factorization.

81204480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106 (or 89 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 27.

The square root of 81204480 is about 9011.3528396129. The cubic root of 81204480 is about 433.0386530395.

Adding to 81204480 its reverse (8440218), we get a palindrome (89644698).

The spelling of 81204480 in words is "eighty-one million, two hundred four thousand, four hundred eighty".