81333328 has 20 divisors (see below), whose sum is σ = 157727008. Its totient is φ = 40629600.

The previous prime is 81333311. The next prime is 81333337. The reversal of 81333328 is 82333318.

It is a super-2 number, since 2×81333328² = 13230220487111168, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81333328.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27103 + ... + 29953.

Almost surely, 2^81333328 is an apocalyptic number.

It is an amenable number.

81333328 is a deficient number, since it is larger than the sum of its proper divisors (76393680).

81333328 is a wasteful number, since it uses less digits than its factorization.

81333328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4642 (or 4636 counting only the distinct ones).

The product of its digits is 10368, while the sum is 31.

The square root of 81333328 is about 9018.4992099573. The cubic root of 81333328 is about 433.2675676657.

The spelling of 81333328 in words is "eighty-one million, three hundred thirty-three thousand, three hundred twenty-eight".