81303928 has 16 divisors (see below), whose sum is σ = 161412480. Its totient is φ = 38260608.

The previous prime is 81303923. The next prime is 81303949. The reversal of 81303928 is 82930318.

It is a super-2 number, since 2×81303928² = 13220657416458368, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a junction number, because it is equal to n+sod(n) for n = 81303893 and 81303902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81303923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 298776 + ... + 299047.

It is an arithmetic number, because the mean of its divisors is an integer number (10088280).

Almost surely, 2^81303928 is an apocalyptic number.

It is an amenable number.

81303928 is a deficient number, since it is larger than the sum of its proper divisors (80108552).

81303928 is a wasteful number, since it uses less digits than its factorization.

81303928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 597846 (or 597842 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 81303928 is about 9016.8690796751. The cubic root of 81303928 is about 433.2153561802.

The spelling of 81303928 in words is "eighty-one million, three hundred three thousand, nine hundred twenty-eight".