81228286 has 4 divisors (see below), whose sum is σ = 121842432. Its totient is φ = 40614142.

The previous prime is 81228281. The next prime is 81228293. The reversal of 81228286 is 68282218.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 68282218 = 2 ⋅34141109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81228281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20307070 + ... + 20307073.

It is an arithmetic number, because the mean of its divisors is an integer number (30460608).

Almost surely, 2^81228286 is an apocalyptic number.

81228286 is a deficient number, since it is larger than the sum of its proper divisors (40614146).

81228286 is a wasteful number, since it uses less digits than its factorization.

81228286 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40614145.

The product of its digits is 24576, while the sum is 37.

The square root of 81228286 is about 9012.6736321693. The cubic root of 81228286 is about 433.0809656104.

The spelling of 81228286 in words is "eighty-one million, two hundred twenty-eight thousand, two hundred eighty-six".