81195556 has 12 divisors (see below), whose sum is σ = 153022492. Its totient is φ = 37474848.

The previous prime is 81195509. The next prime is 81195557. The reversal of 81195556 is 65559118.

It can be written as a sum of positive squares in 2 ways, for example, as 34409956 + 46785600 = 5866^2 + 6840^2 .

It is not an unprimeable number, because it can be changed into a prime (81195557) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 780675 + ... + 780778.

Almost surely, 2^81195556 is an apocalyptic number.

It is an amenable number.

81195556 is a deficient number, since it is larger than the sum of its proper divisors (71826936).

81195556 is a wasteful number, since it uses less digits than its factorization.

81195556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1561470 (or 1561468 counting only the distinct ones).

The product of its digits is 54000, while the sum is 40.

The square root of 81195556 is about 9010.8576728300. The cubic root of 81195556 is about 433.0227894709.

The spelling of 81195556 in words is "eighty-one million, one hundred ninety-five thousand, five hundred fifty-six".