81527320 has 32 divisors (see below), whose sum is σ = 209642400. Its totient is φ = 27952128.

The previous prime is 81527273. The next prime is 81527357. The reversal of 81527320 is 2372518.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 145305 + ... + 145864.

It is an arithmetic number, because the mean of its divisors is an integer number (6551325).

Almost surely, 2^81527320 is an apocalyptic number.

It is an amenable number.

81527320 is an abundant number, since it is smaller than the sum of its proper divisors (128115080).

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

81527320 is a wasteful number, since it uses less digits than its factorization.

81527320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 291187 (or 291183 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 28.

The square root of 81527320 is about 9029.2480307055. The cubic root of 81527320 is about 433.6117632053.

Adding to 81527320 its reverse (2372518), we get a palindrome (83899838).

The spelling of 81527320 in words is "eighty-one million, five hundred twenty-seven thousand, three hundred twenty".