81966288 has 20 divisors (see below), whose sum is σ = 211746368. Its totient is φ = 27322080.

The previous prime is 81966277. The next prime is 81966301. The reversal of 81966288 is 88266918.

It is a Harshad number since it is a multiple of its sum of digits (48), and also a Moran number because the ratio is a prime number: 1707631 = 81966288 / (8 + 1 + 9 + 6 + 6 + 2 + 8 + 8).

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, 853768 + ... + 853863.

Almost surely, 2^81966288 is an apocalyptic number.

It is an amenable number.

81966288 is an abundant number, since it is smaller than the sum of its proper divisors (129780080).

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

81966288 is a wasteful number, since it uses less digits than its factorization.

81966288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1707642 (or 1707636 counting only the distinct ones).

The product of its digits is 331776, while the sum is 48.

The square root of 81966288 is about 9053.5235129755. The cubic root of 81966288 is about 434.3886033592.

The spelling of 81966288 in words is "eighty-one million, nine hundred sixty-six thousand, two hundred eighty-eight".