81332480 has 36 divisors (see below), whose sum is σ = 194819772. Its totient is φ = 32532480.

The previous prime is 81332473. The next prime is 81332543. The reversal of 81332480 is 8423318.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 48888064 + 32444416 = 6992^2 + 5696^2 .

It is a super-2 number, since 2×81332480² = 13229944605900800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30491 + ... + 33050.

Almost surely, 2^81332480 is an apocalyptic number.

81332480 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81332480 is an abundant number, since it is smaller than the sum of its proper divisors (113487292).

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

81332480 is an equidigital number, since it uses as much as digits as its factorization.

81332480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63562 (or 63548 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 81332480 is about 9018.4521953604. The cubic root of 81332480 is about 433.2660618780.

Adding to 81332480 its reverse (8423318), we get a palindrome (89755798).

The spelling of 81332480 in words is "eighty-one million, three hundred thirty-two thousand, four hundred eighty".