81223012 has 24 divisors (see below), whose sum is σ = 155178296. Its totient is φ = 36972288.

The previous prime is 81222983. The next prime is 81223031. The reversal of 81223012 is 21032218.

It can be written as a sum of positive squares in 4 ways, for example, as 23097636 + 58125376 = 4806^2 + 7624^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6903 + ... + 14494.

Almost surely, 2^81223012 is an apocalyptic number.

It is an amenable number.

81223012 is a deficient number, since it is larger than the sum of its proper divisors (73955284).

81223012 is a wasteful number, since it uses less digits than its factorization.

81223012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21487 (or 21485 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 81223012 is about 9012.3810394368. The cubic root of 81223012 is about 433.0715923630.

The spelling of 81223012 in words is "eighty-one million, two hundred twenty-three thousand, twelve".