81541320 has 64 divisors (see below), whose sum is σ = 279573120. Its totient is φ = 18637824.

The previous prime is 81541319. The next prime is 81541337. The reversal of 81541320 is 2314518.

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47697 + ... + 49376.

It is an arithmetic number, because the mean of its divisors is an integer number (4368330).

Almost surely, 2^81541320 is an apocalyptic number.

It is an amenable number.

81541320 is an abundant number, since it is smaller than the sum of its proper divisors (198031800).

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

81541320 is a wasteful number, since it uses less digits than its factorization.

81541320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97094 (or 97090 counting only the distinct ones).

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

The square root of 81541320 is about 9030.0232557840. The cubic root of 81541320 is about 433.6365819501.

Adding to 81541320 its reverse (2314518), we get a palindrome (83855838).

The spelling of 81541320 in words is "eighty-one million, five hundred forty-one thousand, three hundred twenty".