81496520 has 128 divisors (see below), whose sum is σ = 222566400. Its totient is φ = 26265600.

The previous prime is 81496483. The next prime is 81496531. The reversal of 81496520 is 2569418.

It is a super-2 number, since 2×81496520² = 13283365544220800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 355766 + ... + 355994.

It is an arithmetic number, because the mean of its divisors is an integer number (1738800).

Almost surely, 2^81496520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81496520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111283200).

81496520 is an abundant number, since it is smaller than the sum of its proper divisors (141069880).

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

81496520 is a wasteful number, since it uses less digits than its factorization.

81496520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319 (or 315 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 81496520 is about 9027.5423012025. The cubic root of 81496520 is about 433.5571519639.

The spelling of 81496520 in words is "eighty-one million, four hundred ninety-six thousand, five hundred twenty".