81314520 has 96 divisors (see below), whose sum is σ = 283791600. Its totient is φ = 18584832.

The previous prime is 81314503. The next prime is 81314531. The reversal of 81314520 is 2541318.

It is a super-2 number, since 2×81314520² = 13224102325660800, which contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1035 + ... + 12794.

Almost surely, 2^81314520 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 81314520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141895800).

81314520 is an abundant number, since it is smaller than the sum of its proper divisors (202477080).

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

81314520 is a wasteful number, since it uses less digits than its factorization.

81314520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13857 (or 13846 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 24.

The square root of 81314520 is about 9017.4564041086. The cubic root of 81314520 is about 433.2341679725.

Adding to 81314520 its reverse (2541318), we get a palindrome (83855838).

The spelling of 81314520 in words is "eighty-one million, three hundred fourteen thousand, five hundred twenty".