81521514 has 48 divisors (see below), whose sum is σ = 186732000. Its totient is φ = 25632288.

The previous prime is 81521501. The next prime is 81521527. The reversal of 81521514 is 41512518.

It is an interprime number because it is at equal distance from previous prime (81521501) and next prime (81521527).

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 119017 + ... + 119699.

It is an arithmetic number, because the mean of its divisors is an integer number (3890250).

Almost surely, 2^81521514 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81521514, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93366000).

81521514 is an abundant number, since it is smaller than the sum of its proper divisors (105210486).

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

81521514 is a wasteful number, since it uses less digits than its factorization.

81521514 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1059 (or 1056 counting only the distinct ones).

The product of its digits is 1600, while the sum is 27.

The square root of 81521514 is about 9028.9265142651. The cubic root of 81521514 is about 433.6014696838.

The spelling of 81521514 in words is "eighty-one million, five hundred twenty-one thousand, five hundred fourteen".