81522480 has 320 divisors, whose sum is σ = 303730560. Its totient is φ = 17891328.

The previous prime is 81522461. The next prime is 81522499. The reversal of 81522480 is 8422518.

It is an interprime number because it is at equal distance from previous prime (81522461) and next prime (81522499).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1538134 + ... + 1538186.

It is an arithmetic number, because the mean of its divisors is an integer number (949158).

Almost surely, 2^81522480 is an apocalyptic number.

81522480 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 81522480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (151865280).

81522480 is an abundant number, since it is smaller than the sum of its proper divisors (222208080).

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

81522480 is a wasteful number, since it uses less digits than its factorization.

81522480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 30.

The square root of 81522480 is about 9028.9800088382. The cubic root of 81522480 is about 433.6031823498.

Adding to 81522480 its reverse (8422518), we get a palindrome (89944998).

The spelling of 81522480 in words is "eighty-one million, five hundred twenty-two thousand, four hundred eighty".