81210480 has 80 divisors (see below), whose sum is σ = 271128480. Its totient is φ = 19989504.

The previous prime is 81210473. The next prime is 81210487. The reversal of 81210480 is 8401218.

It is an interprime number because it is at equal distance from previous prime (81210473) and next prime (81210487).

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 81210480.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81210487) 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 15 ways as a sum of consecutive naturals, for example, 9895 + ... + 16134.

It is an arithmetic number, because the mean of its divisors is an integer number (3389106).

Almost surely, 2^81210480 is an apocalyptic number.

81210480 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81210480 is an abundant number, since it is smaller than the sum of its proper divisors (189918000).

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

81210480 is a wasteful number, since it uses less digits than its factorization.

81210480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26058 (or 26052 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 81210480 is about 9011.6857468511. The cubic root of 81210480 is about 433.0493181651.

Adding to 81210480 its reverse (8401218), we get a palindrome (89611698).

The spelling of 81210480 in words is "eighty-one million, two hundred ten thousand, four hundred eighty".