81222692 has 6 divisors (see below), whose sum is σ = 142139718. Its totient is φ = 40611344.

The previous prime is 81222689. The next prime is 81222703. The reversal of 81222692 is 29622218.

It can be written as a sum of positive squares in only one way, i.e., 80174116 + 1048576 = 8954^2 + 1024^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 10152833 + ... + 10152840.

It is an arithmetic number, because the mean of its divisors is an integer number (23689953).

Almost surely, 2^81222692 is an apocalyptic number.

It is an amenable number.

81222692 is a deficient number, since it is larger than the sum of its proper divisors (60917026).

81222692 is a wasteful number, since it uses less digits than its factorization.

81222692 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20305677 (or 20305675 counting only the distinct ones).

The product of its digits is 6912, while the sum is 32.

The square root of 81222692 is about 9012.3632860643. The cubic root of 81222692 is about 433.0710236281.

The spelling of 81222692 in words is "eighty-one million, two hundred twenty-two thousand, six hundred ninety-two".