81303530 has 96 divisors (see below), whose sum is σ = 190753920. Its totient is φ = 24393600.

The previous prime is 81303529. The next prime is 81303539. The reversal of 81303530 is 3530318.

It is a super-2 number, since 2×81303530² = 13220527980921800, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81303496 and 81303505.

It is not an unprimeable number, because it can be changed into a prime (81303539) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 245465 + ... + 245795.

It is an arithmetic number, because the mean of its divisors is an integer number (1987020).

Almost surely, 2^81303530 is an apocalyptic number.

81303530 is an abundant number, since it is smaller than the sum of its proper divisors (109450390).

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

81303530 is a wasteful number, since it uses less digits than its factorization.

81303530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396 (or 385 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 81303530 is about 9016.8470099032. The cubic root of 81303530 is about 433.2146492853.

Adding to 81303530 its reverse (3530318), we get a palindrome (84833848).

The spelling of 81303530 in words is "eighty-one million, three hundred three thousand, five hundred thirty".